1
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Bacauanu V, Merz ZN, Hua ZL, Lang SB. Nickel-Catalyzed Antibody Bioconjugation. J Am Chem Soc 2023; 145:25842-25849. [PMID: 37950853 DOI: 10.1021/jacs.3c10185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2023]
Abstract
New biocompatible methods for post-translational protein modification are challenging to develop but crucial to create improved chemical probes and optimize next-generation biologic therapies such as antibody-drug conjugates (ADCs). Herein, we describe the bottom-up construction of an aqueous nickel-catalyzed cross-coupling for the chemospecific arylation of cysteine residues on peptides and proteins and its use for the preparation of ADCs. A variety of arene linkages are exemplified, enabling the incorporation of small molecules, probes, and cytotoxic payloads. The utility of this new bioconjugation platform in a drug discovery setting is highlighted by the construction of novel ADCs with target-mediated in vitro cytotoxic activity.
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Affiliation(s)
- Vlad Bacauanu
- Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
| | - Zoe N Merz
- Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
| | - Zhong L Hua
- Discovery Oncology, Merck & Co., Inc., South San Francisco, California 94080, United States
| | - Simon B Lang
- Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
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2
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Merchant RR, Lang SB, Yu T, Zhao S, Qi Z, Suzuki T, Bao J. A General One-Pot Protocol for Hindered N-Alkyl Azaheterocycles from Tertiary Carboxylic Acids. Org Lett 2020; 22:4180-4184. [PMID: 32383385 DOI: 10.1021/acs.orglett.0c01254] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this letter, we report a general one-pot strategy that utilizes three elementary steps (decarboxylative hydrazination, Boc deprotection, and heterocycle condensation) to regioselectively prepare hindered C(sp3) substituted pyrazoles and triazoles. The operational simplicity of this sequence and ubiquity of tertiary carboxylic acids allow rapid access to hindered N-alkyl azaheterocycles that will be useful to practitioners of medicinal chemistry and agro-chemistry.
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Affiliation(s)
- Rohan R Merchant
- Department of Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
| | - Simon B Lang
- Department of Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
| | - Tingting Yu
- IDSU, WuXi AppTec Co., Ltd., Shanghai 200131, China
| | | | - Zhiqi Qi
- IDSU, WuXi AppTec Co., Ltd., Shanghai 200131, China
| | - Takao Suzuki
- IDSU, WuXi AppTec Co., Ltd., Shanghai 200131, China
| | - Jianming Bao
- Department of Discovery Chemistry, Merck & Co., Inc., South San Francisco, California 94080, United States
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3
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Cartwright KC, Lang SB, Tunge JA. Photoinduced Kochi Decarboxylative Elimination for the Synthesis of Enamides and Enecarbamates from N-Acyl Amino Acids. J Org Chem 2019; 84:2933-2940. [PMID: 30785754 DOI: 10.1021/acs.joc.9b00167] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Decarboxylative elimination of easily accessible N-acyl amino acids to provide enamide and enecarbamate building blocks has been realized through the combination of an organophotoredox catalyst and copper acetate as the terminal oxidant. This operationally simple process utilizes inexpensive and readily available reagents without preactivation of the carboxylic acid. Enamides and enecarbamates are now accessible directly from N-acyl amino acids consequently improving upon the utility of Kochi's oxidative decarboxylation of carboxylic acids.
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Affiliation(s)
- Kaitie C Cartwright
- Department of Chemistry , The University of Kansas , 2010 Malott Hall, 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Simon B Lang
- Department of Chemistry , The University of Kansas , 2010 Malott Hall, 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Jon A Tunge
- Department of Chemistry , The University of Kansas , 2010 Malott Hall, 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
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4
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Phelan JP, Lang SB, Sim J, Berritt S, Peat AJ, Billings K, Fan L, Molander GA. Open-Air Alkylation Reactions in Photoredox-Catalyzed DNA-Encoded Library Synthesis. J Am Chem Soc 2019; 141:3723-3732. [PMID: 30753065 DOI: 10.1021/jacs.9b00669] [Citation(s) in RCA: 220] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
DNA-encoded library (DEL) technology is a powerful tool commonly used by the pharmaceutical industry for the identification of compounds with affinity to biomolecular targets. Success in this endeavor lies in sampling diverse chemical libraries. However, current DELs tend to be deficient in C(sp3) carbon counts. We report unique solutions to the challenge of increasing both the chemical diversity of these libraries and their C(sp3) carbon counts by merging Ni/photoredox dual catalytic C(sp2)-C(sp3) cross-coupling as well as photoredox-catalyzed radical/polar crossover alkylation protocols with DELs. The successful integration of multiple classes of radical sources enables the rapid incorporation of a diverse set of alkyl fragments.
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Affiliation(s)
- James P Phelan
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Simon B Lang
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Jaehoon Sim
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Simon Berritt
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Andrew J Peat
- GlaxoSmithKline , 1250 South Collegeville Road , Collegeville , Pennsylvania 19426 , United States
| | - Katelyn Billings
- GlaxoSmithKline , 200 Cambridge Park Drive , Cambridge , Massachusetts 02140 , United States
| | - Lijun Fan
- GlaxoSmithKline , 200 Cambridge Park Drive , Cambridge , Massachusetts 02140 , United States
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
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5
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Noland WE, Huisenga MP, Herzig RJ, Rosenow JA, Kim H, Kroll NJ, Nesmelov A, Johnson BT, Duncan NS, Ratanayanon J, Yue RA, Xiong K, Ong BK, Vo DT, Klein ND, Lang SB, Riley JK, Daniels SP, Tritch KJ. A Diels–Alder/Ene Cascade Leading to 5‐(Pyrrolidin‐3‐yl)thieno[3,2‐e]isoindoles from Ketone‐derived 2‐Vinylthiophenes andN‐Phenylmaleimide. J Heterocycl Chem 2018. [DOI: 10.1002/jhet.3327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Wayland E. Noland
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | | | - Ryan J. Herzig
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - John A. Rosenow
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Hoyeon Kim
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Neil J. Kroll
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Andrei Nesmelov
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | | | - Nathan S. Duncan
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | | | - Ruixian A. Yue
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Kenny Xiong
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Bee K. Ong
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Diane T. Vo
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Nathan D. Klein
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Simon B. Lang
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Jacob K. Riley
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Steven P. Daniels
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
| | - Kenneth J. Tritch
- Department of ChemistryUniversity of Minnesota Minneapolis MN 55455 USA
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6
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Phelan JP, Lang SB, Compton JS, Kelly CB, Dykstra R, Gutierrez O, Molander GA. Redox-Neutral Photocatalytic Cyclopropanation via Radical/Polar Crossover. J Am Chem Soc 2018; 140:8037-8047. [PMID: 29916711 DOI: 10.1021/jacs.8b05243] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A benchtop stable, bifunctional reagent for the redox-neutral cyclopropanation of olefins has been developed. Triethylammonium bis(catecholato)iodomethylsilicate can be readily prepared on multigram scale. Using this reagent in combination with an organic photocatalyst and visible light, cyclopropanation of an array of olefins, including trifluoromethyl- and pinacolatoboryl-substituted alkenes, can be accomplished in a matter of hours. The reaction is highly tolerant of traditionally reactive functional groups (carboxylic acids, basic heterocycles, alkyl halides, etc.) and permits the chemoselective cyclopropanation of polyolefinated compounds. Mechanistic interrogation revealed that the reaction proceeds via a rapid anionic 3- exo- tet ring closure, a pathway consistent with experimental and computational data.
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Affiliation(s)
- James P Phelan
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Simon B Lang
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Jordan S Compton
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Christopher B Kelly
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
| | - Ryan Dykstra
- Department of Chemistry and Biochemistry , University of Maryland , College Park , Maryland 20742 , United States
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry , University of Maryland , College Park , Maryland 20742 , United States
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , United States
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7
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Cabrera-Afonso MJ, Lu ZP, Kelly CB, Lang SB, Dykstra R, Gutierrez O, Molander GA. Engaging sulfinate salts via Ni/photoredox dual catalysis enables facile C sp2 -SO 2R coupling. Chem Sci 2018; 9:3186-3191. [PMID: 29732101 PMCID: PMC5916223 DOI: 10.1039/c7sc05402e] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/21/2018] [Indexed: 01/04/2023] Open
Abstract
This report details the development and implementation of a strategy to construct aryl- and heteroaryl sulfones via Ni/photoredox dual catalysis. Using aryl sulfinate salts, the C-S bond can be forged at room temperature under base-free conditions. An array of aryl- and heteroaryl halides are compatible with this approach. The broad tolerance and mild nature of the described reaction could potentially be employed to prepare sulfones with biological relevance (e.g., in bioconjugation, drug substance synthesis, etc.) as demonstrated in the synthesis of drug-like compounds or their precursors. When paired with existing Ni/photoredox chemistry for Csp3 -Csp2 cross-coupling, an array of diverse sulfone scaffolds can be readily assembled from bifunctional electrophiles. A mechanistic manifold consistent with experimental and computational data is presented.
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Affiliation(s)
- María Jesús Cabrera-Afonso
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Zhi-Peng Lu
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Christopher B Kelly
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Simon B Lang
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Ryan Dykstra
- Department of Chemistry and Biochemistry , University of Maryland , College Park , Maryland 20742 , USA .
| | - Osvaldo Gutierrez
- Department of Chemistry and Biochemistry , University of Maryland , College Park , Maryland 20742 , USA .
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
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8
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Phelan JP, Wiles RJ, Lang SB, Kelly CB, Molander GA. Rapid access to diverse, trifluoromethyl-substituted alkenes using complementary strategies. Chem Sci 2018; 9:3215-3220. [PMID: 29732105 PMCID: PMC5916225 DOI: 10.1039/c7sc05420c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 02/21/2018] [Indexed: 12/12/2022] Open
Abstract
Two synergistic approaches to the facile assembly of complex α-trifluoromethyl alkenes are described. Using α-trifluoromethyl-β-silyl alcohols as masked trifluoromethyl alkenes, cross-coupling or related functionalization processes at distal electrophilic sites can be executed without inducing Peterson elimination. Subsequent Lewis acidic activation affords functionalized α-trifluoromethyl alkenes. Likewise, the development of a novel α-trifluoromethylvinyl trifluoroborate reagent complements this approach and allows a one-step cross-coupling of (hetero)aryl halides to access a broad array of complex α-trifluoromethyl alkenes.
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Affiliation(s)
- James P Phelan
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Rebecca J Wiles
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Simon B Lang
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Christopher B Kelly
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
| | - Gary A Molander
- Roy and Diana Vagelos Laboratories , Department of Chemistry , University of Pennsylvania , 231 South 34th Street , Philadelphia , Pennsylvania 19104-6323 , USA .
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9
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Phelan JP, Wiles RJ, Lang SB, Kelly CB, Molander GA. Correction: Rapid access to diverse, trifluoromethyl-substituted alkenes using complementary strategies. Chem Sci 2018; 9:5119. [PMID: 30090294 PMCID: PMC6062420 DOI: 10.1039/c8sc90109k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 05/17/2018] [Indexed: 11/21/2022] Open
Abstract
Correction for ‘Rapid access to diverse, trifluoromethyl-substituted alkenes using complementary strategies’ by James P. Phelan et al., Chem. Sci., 2018, 9, 3215–3220.
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Affiliation(s)
- James P. Phelan
- Roy and Diana Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Rebecca J. Wiles
- Roy and Diana Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Simon B. Lang
- Roy and Diana Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Christopher B. Kelly
- Roy and Diana Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Gary A. Molander
- Roy and Diana Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
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10
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Lang SB, Wiles RJ, Kelly CB, Molander GA. Photoredox Generation of Carbon-Centered Radicals Enables the Construction of 1,1-Difluoroalkene Carbonyl Mimics. Angew Chem Int Ed Engl 2017; 56:15073-15077. [PMID: 28960656 PMCID: PMC5688010 DOI: 10.1002/anie.201709487] [Citation(s) in RCA: 234] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Indexed: 11/08/2022]
Abstract
Described is a facile, scalable route to access functional-group-rich gem-difluoroalkenes. Using visible-light-activated catalysts in conjunction with an arsenal of carbon-radical precursors, an array of trifluoromethyl-substituted alkenes undergoes radical defluorinative alkylation. Nonstabilized primary, secondary, and tertiary radicals can be used to install functional groups in a convergent manner, which would otherwise be challenging by two-electron pathways. The process readily extends to other perfluoroalkyl-substituted alkenes. In addition, we report the development of an organotrifluoroborate reagent to expedite the synthesis of the requisite trifluoromethyl-substituted alkene starting materials.
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Affiliation(s)
- Simon B Lang
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Rebecca J Wiles
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Christopher B Kelly
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
| | - Gary A Molander
- Department of Chemistry, University of Pennsylvania, Roy and Diana Vagelos Laboratories, 231 S. 34th Street, Philadelphia, PA, 19104-6323, USA
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11
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Lang SB, Wiles RJ, Kelly CB, Molander GA. Photoredox Generation of Carbon-Centered Radicals Enables the Construction of 1,1-Difluoroalkene Carbonyl Mimics. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709487] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Simon B. Lang
- Department of Chemistry; University of Pennsylvania; Roy and Diana Vagelos Laboratories; 231 S. 34th Street Philadelphia PA 19104-6323 USA
| | - Rebecca J. Wiles
- Department of Chemistry; University of Pennsylvania; Roy and Diana Vagelos Laboratories; 231 S. 34th Street Philadelphia PA 19104-6323 USA
| | - Christopher B. Kelly
- Department of Chemistry; University of Pennsylvania; Roy and Diana Vagelos Laboratories; 231 S. 34th Street Philadelphia PA 19104-6323 USA
| | - Gary A. Molander
- Department of Chemistry; University of Pennsylvania; Roy and Diana Vagelos Laboratories; 231 S. 34th Street Philadelphia PA 19104-6323 USA
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12
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Matsui JK, Lang SB, Heitz DR, Molander GA. Photoredox-Mediated Routes to Radicals: The Value of Catalytic Radical Generation in Synthetic Methods Development. ACS Catal 2017; 7:2563-2575. [PMID: 28413692 PMCID: PMC5388068 DOI: 10.1021/acscatal.7b00094] [Citation(s) in RCA: 412] [Impact Index Per Article: 58.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/17/2017] [Indexed: 01/19/2023]
Abstract
Photoredox catalysis has experienced a revitalized interest from the synthesis community during the past decade. For example, photoredox/Ni dual catalysis protocols have been developed to overcome several inherent limitations of palladium-catalyzed cross-couplings by invoking a single-electron transmetalation pathway. This Perspective highlights advances made by our laboratory since the inception of the photoredox/Ni cross-coupling of benzyltrifluoroborates with aryl bromides. In addition to broadening the scope of trifluoroborate coupling partners, research using readily oxidized hypervalent silicates as radical precursors that demonstrate functional group compatibility is highlighted. The pursuit of electrophilic coupling partners beyond (hetero)aryl bromides has also led to the incorporation of several new classes of C(sp2)-hybridized substrates into light-mediated cross-coupling. Advances to expand the radical toolbox by utilizing feedstock chemicals (e.g., aldehydes) to access radicals that were previously inaccessible from trifluoroborates and silicates are also emphasized. Additionally, several organic photocatalysts have been investigated as replacements for their expensive iridium- and ruthenium-based counterparts. Lastly, the net C-H functionalization of the radical partner in an effort to improve atom economy is presented. An underlying theme in all of these studies is the value of generating radicals in a catalytic manner, rather than stoichiometrically.
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Affiliation(s)
- Jennifer K. Matsui
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Simon B. Lang
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Drew R. Heitz
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
| | - Gary A. Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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13
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Lang SB, Cartwright KC, Welter RS, Locascio TM, Tunge JA. Photocatalytic Aminodecarboxylation of Carboxylic Acids. European J Org Chem 2016; 2016:3331-3334. [PMID: 28936118 PMCID: PMC5604885 DOI: 10.1002/ejoc.201600620] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Indexed: 11/06/2022]
Abstract
Aminodecarboxylation of unactivated alkyl carboxylic acids has been accomplished utilizing an organic photocatalyst. This operationally simple reaction utilizes readily available carboxylic acids to chemoselectively generate reactive alkyl intermediates that are not accessible via conventional two-electron pathways. The organic radical intermediates are efficiently trapped with electrophilic diazo compounds to provide aminated alkanes.
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Affiliation(s)
- Simon B Lang
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045, (USA)
| | - Kaitie C Cartwright
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045, (USA)
| | - Richard S Welter
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045, (USA)
| | - Theresa M Locascio
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045, (USA)
| | - Jon A Tunge
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045, (USA)
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14
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Lang SB, O'Nele KM, Douglas JT, Tunge JA. Dual Catalytic Decarboxylative Allylations of α-Amino Acids and Their Divergent Mechanisms. Chemistry 2015; 21:18589-93. [PMID: 26526115 DOI: 10.1002/chem.201503644] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Indexed: 02/04/2023]
Abstract
The room temperature radical decarboxylative allylation of N-protected α-amino acids and esters has been accomplished via a combination of palladium and photoredox catalysis to provide homoallylic amines. Mechanistic investigations revealed that the stability of the α-amino radical, which is formed by decarboxylation, dictates the predominant reaction pathway between competing mechanisms.
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Affiliation(s)
- Simon B Lang
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045 (USA)
| | - Kathryn M O'Nele
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045 (USA)
| | - Justin T Douglas
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045 (USA)
| | - Jon A Tunge
- Department of Chemistry, The University of Kansas, 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence KS 66045 (USA).
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15
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Noland WE, Kroll NJ, Huisenga MP, Yue RA, Lang SB, Klein ND, Tritch KJ. Crystal structure of (1S,2R,6R,7R,8S,12S)-4,10,17-triphenyl-15-thia-4,10-diaza-penta-cyclo[5.5.5.0(1,16).0(2,6).0(8,12)]hepta-deca-13,16-diene-3,5,9,11-tetrone p-xylene hemisolvate. Acta Crystallogr Sect E Struct Rep Online 2014; 70:550-4. [PMID: 25552990 PMCID: PMC4257460 DOI: 10.1107/s1600536814025094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 11/16/2014] [Indexed: 11/23/2022]
Abstract
A novel meso bicyclo[2.2.2]octene-based compound was obtained from an attempted Diels–Alder reaction. It crystallizes from p-xylene as a hemisolvate. The title tetrone compound, C32H22N2O4S· 0.5C8H10, is the major product (50% yield) of an attempted Diels–Alder reaction of 2-(α-styryl)thiophene with N-phenylmaleimide (2 equivalents) in toluene. Recrystallization of the resulting powder from p-xylene gave the title hemisolvate; the p-xylene molecule is located about an inversion center. In the crystal, the primary tetrone contacts are between a carbonyl O atom and the four flagpole H atoms of the bicyclo[2.2.2]octene core, forming chains along [001].
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Affiliation(s)
- Wayland E Noland
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Neil J Kroll
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Matthew P Huisenga
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Ruixian A Yue
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Simon B Lang
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Nathan D Klein
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
| | - Kenneth J Tritch
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455-0431, USA
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Abstract
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A combination of
photoredox and palladium catalysis has been employed
to facilitate the room temperature decarboxylative allylation of recalcitrant
α-amino and phenylacetic allyl esters. This operationally simple
process produces CO2 as the only byproduct and provides
direct access to allylated alkanes. After photochemical oxidation,
the carboxylate undergoes radical decarboxylation to site-specifically
generate radical intermediates which undergo allylation. A radical
dual catalysis mechanism is proposed. Free phenylacetic acids were
also allylated utilizing similar reactions conditions.
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Affiliation(s)
- Simon B Lang
- Department of Chemistry, The University of Kansas , 2010 Malott Hall, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045, United States
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17
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Abstract
Herein we present the development of asymmetric deacylative allylation of ketone enolates. The reaction directly couples readily available ketone pronucleophiles with allylic alcohols using facile retro-Claisen cleavage to form reactive intermediates in situ. The simplicity and robustness of the reaction conditions is demonstrated by the preparation of >6 g of an allylated tetralone from commercially available materials. Furthermore, use of nonracemic PHOX ligands allows intermolecular formation of quaternary stereocenters directly from allylic alcohols.
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Affiliation(s)
- Alexander J Grenning
- Department of Chemistry, The University of Kansas, 1251 Wescoe Hall Drive, Lawrence, Kansas 66045-7582, United States
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18
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Tsurumi T, Bell AJ, Clem PG, Gruverman A, Kholkin A, Lang SB, Rhee S, Trolier-McKinstry S, Uchiyama K. Introduction to the special issue on the applications of ferroelectrics--part II. IEEE Trans Ultrason Ferroelectr Freq Control 2008; 55:938-941. [PMID: 18519191 DOI: 10.1109/tuffc.2008.735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- T Tsurumi
- Tokyo Institute of Technology, Tokyo, Japan
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19
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Lang SB, Putley EH. Pyroelectric materials as sensors for IR detectors: a history. Appl Opt 1982; 21:2304. [PMID: 20396025 DOI: 10.1364/ao.21.002304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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20
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Lang SB. Sophisticated Designs:
The Mechanical Properties of Biological Materials
. Papers from a symposium, Leeds, England, Sept. 1979. Published for the Society for Experimental Biology by Cambridge University Press, New York, 1981. x, 514 pp., illus. $69.50. Symposia of the Society for Experimental Biology, No. 34. Science 1981; 213:1243-4. [PMID: 17744755 DOI: 10.1126/science.213.4513.1243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Sollish BD, Frei EH, Hammerman E, Lang SB, Moshitzky M. Microprocessor-assisted screening techniques. Isr J Med Sci 1981; 17:859-64. [PMID: 7309473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The important features of microprocessor design of medical instrumentation are discussed, and the Mammoscan dielectric breast scanner being developed in our laboratories is given as a specific example. The principles of dielectric breast scanning are explained, and the implementation of the technique in a working Mammoscan is is described. Typical results of Mammoscan examinations are given, including both normal and suspicious findings. Preliminary attempts at image classification are discussed, as well as the necessity of large-scale clinical data gathering for improving classification methods. The use of microprocessors makes devices such as the Mammoscan possible, both because of the power of microprocessor control and number handling, and because of its ability to store examination data locally and analyze it off-line at a central location.
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22
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Abstract
Quantitative pyroelectric measurements were made on the leaves of the palmlike plant Encephalartos. A pyroelectric response almost 50 times higher than the normal one could be induced by a small bias electric field, offering a means for highly increasing the efficiency of conversion of thermal to electrical energy. No evidence of ferroelectricity was found.
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24
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Fukada E, Lang SB, Mascarenhas S, Pilla AA, Shamos MH. Panel discussion: The electrophysical and electrochemical properties of living tissue. Ann N Y Acad Sci 1974; 238:228-35. [PMID: 4531263 DOI: 10.1111/j.1749-6632.1974.tb26792.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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26
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27
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Abstract
The elastic stiffness coefficients of dried bovine phalanx and femur and of fresh bovine phalanx were measured by an ultrasonic technique. An analysis of the crystallographic structure of the principal components of bone and its piezoelectric and pyroelectric behavior showed that bone is a texture that has the same elastic coeffcient matrix as a hexagonal single crystal. The five elastic stiffness coefficients of fresh phalanx are: C(1l), 1.97; C(12), 1.21; C(13), 1.26; C(33), 3.20; and C(44), 0.54 (all in units of 10(11) dynes per square centimeter). Value of axial and transverse Young's and shear moduli, compressibility, and the three Poisson's ratios were calculated.
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