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Levi Knippel J, Ni AZ, Schuppe AW, Buchwald SL. A General Strategy for the Asymmetric Preparation of α-Stereogenic Allyl Silanes, Germanes, and Boronate Esters via Dual Copper Hydride- and Palladium-Catalysis. Angew Chem Int Ed Engl 2022; 61:e202212630. [PMID: 36137941 PMCID: PMC9828222 DOI: 10.1002/anie.202212630] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 08/26/2022] [Indexed: 01/12/2023]
Abstract
α-Stereogenic allyl metalloids are versatile synthetic intermediates which can undergo various stereocontrolled transformations. Most existing methods to prepare α-stereogenic allyl metalloids involve multi-step sequences that curtail the number of compatible substrates and are limited to the synthesis of boronates. Here, we report a general method for the enantioselective preparation of α-stereogenic allyl metalloids utilizing dual CuH- and Pd-catalysis. This approach leverages a stereoretentive Cu-to-Pd transmetalation of an in situ generated alkyl copper species to allow access to enantioenriched allyl silanes, germanes, and boronate esters with broad functional group compatibility.
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Affiliation(s)
- James Levi Knippel
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
| | - Anton Z Ni
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
| | - Alexander W Schuppe
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139, USA
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2
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Schuppe AW, Liu Y, Gonzalez-Hurtado E, Zhao Y, Jiang X, Ibarraran S, Huang D, Wang E, Lee J, Loria JP, Dixit VD, Li X, Newhouse TR. Unified Total Synthesis of the Limonoid Alkaloids: Strategies for the De Novo Synthesis of Highly Substituted Pyridine Scaffolds. Chem 2022; 8:2856-2887. [PMID: 37396824 PMCID: PMC10311986 DOI: 10.1016/j.chempr.2022.09.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [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] [Indexed: 11/23/2022]
Abstract
Highly substituted pyridine scaffolds are found in many biologically active natural products and therapeutics. Accordingly, numerous complementary de novo approaches to obtain differentially substituted pyridines have been disclosed. This article delineates the evolution of the synthetic strategies designed to assemble the demanding tetrasubstituted pyridine core present in the limonoid alkaloids isolated from Xylocarpus granatum, including xylogranatopyridine B, granatumine A and related congeners. In addition, NMR calculations suggested structural misassignment of several limonoid alkaloids, and predicted their C3-epimers as the correct structures, which was further validated unequivocally through chemical synthesis. The materials produced in this study were evaluated for cytotoxicity, anti-oxidant effects, anti-inflammatory action, PTP1B and Nlrp3 inflammasome inhibition, which led to compelling anti-inflammatory activity and anti-oxidant effects being discovered.
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Affiliation(s)
- Alexander W. Schuppe
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Yannan Liu
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Elsie Gonzalez-Hurtado
- Department of Pathology, Immunobiology, Comparative Medicine, Yale School of Medicine, 310 Cedar Street, New Haven, Connecticut 06520, United States
| | - Yizhou Zhao
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Xuefeng Jiang
- College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou 310018, P. R. China
| | - Sebastian Ibarraran
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - David Huang
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Emma Wang
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Jaehoo Lee
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - J. Patrick Loria
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Vishwa Deep Dixit
- Department of Pathology, Immunobiology, Comparative Medicine, Yale School of Medicine, 310 Cedar Street, New Haven, Connecticut 06520, United States
| | - Xin Li
- College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Rd, Hangzhou 310018, P. R. China
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
- Lead contact
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Losacco GL, Bennett R, Ahmad IAH, Barrientos RC, DaSilva JO, Dong Y, Schuppe AW, Wang Z, Aiken S, Mangion I, Aggarwal VK, Regalado EL. Dual‐Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | | | | | | | - Yuyang Dong
- MIT: Massachusetts Institute of Technology Chemistry UNITED STATES
| | | | - Zeshu Wang
- University of Bristol School of Chemistry School of Chemistry UNITED STATES
| | - Sheenagh Aiken
- University of Bristol School of Chemistry School of Chemistry UNITED STATES
| | | | | | - Erik L. Regalado
- Merck Research Laboratories Process Research & Development 126E. Lincoln Ave.PO Box 2000 07065 Rahway UNITED STATES
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4
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Losacco GL, Bennett R, Ahmad IAH, Barrientos RC, DaSilva JO, Dong Y, Schuppe AW, Wang Z, Aiken S, Mangion I, Aggarwal VK, Regalado EL. Dual‐Gradient Unified Chromatography: A New Paradigm for Versatility in Simultaneous Multicomponent Analysis. Angew Chem Int Ed Engl 2022; 61:e202208854. [DOI: 10.1002/anie.202208854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Indexed: 11/05/2022]
Affiliation(s)
| | | | | | | | | | - Yuyang Dong
- MIT: Massachusetts Institute of Technology Chemistry UNITED STATES
| | | | - Zeshu Wang
- University of Bristol School of Chemistry School of Chemistry UNITED STATES
| | - Sheenagh Aiken
- University of Bristol School of Chemistry School of Chemistry UNITED STATES
| | | | | | - Erik L. Regalado
- Merck Research Laboratories Process Research & Development 126E. Lincoln Ave.PO Box 2000 07065 Rahway UNITED STATES
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Dong Y, Schuppe AW, Mai BK, Liu P, Buchwald SL. Confronting the Challenging Asymmetric Carbonyl 1,2-Addition Using Vinyl Heteroarene Pronucleophiles: Ligand-Controlled Regiodivergent Processes through a Dearomatized Allyl-Cu Species. J Am Chem Soc 2022; 144:5985-5995. [PMID: 35341240 PMCID: PMC9202959 DOI: 10.1021/jacs.2c00734] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The selective reductive coupling of vinyl heteroarenes with aldehydes and ketones represents a versatile approach for the rapid construction of enantiomerically enriched secondary and tertiary alcohols, respectively. Herein, we demonstrate a CuH-catalyzed regiodivergent coupling of vinyl heteroarenes with carbonyl-containing electrophiles, in which the selectivity is controlled by the ancillary ligand. This approach leverages an in situ generated benzyl- or dearomatized allyl-Cu intermediate, yielding either the dearomatized or exocyclic addition products, respectively. The method exhibits excellent regio-, diastereo-, and enantioselectivity and tolerates a range of common functional groups and heterocycles. The dearomative pathway allows direct access to a variety of functionalized saturated heterocyclic structures. The reaction mechanism was probed using a combination of experimental and computational approach. Density functional theory studies suggest that the ligand-controlled regioselectivity results from the C-H/π interaction and steric repulsion in transition states, leading to the major and minor regioisomers, respectively. Hydrocupration of vinyl heteroarene pronucleophile is the enantiodetermining step, whereas the diastereoselectivity is enforced by steric interactions between the benzylic or allyl-Cu intermediate and carbonyl-containing substrates in a six-membered cyclic transition state.
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Affiliation(s)
- Yuyang Dong
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander W Schuppe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Binh Khanh Mai
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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Liu Y, Schuppe AW, Zhao Y, Lee J, Newhouse TR. Synthesis of (-)-melazolide B, a degraded limonoid, from a natural terpene precursor. Tetrahedron Chem 2022; 1:100011. [PMID: 38606284 PMCID: PMC11008529 DOI: 10.1016/j.tchem.2022.100011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Degraded limonoids are a subclass of limonoid natural products that derive from ring-intact or ring-rearranged limonoids. Establishment of robust synthetic routes to access them could provide valuable materials to identify the simplest active pharmacophore responsible for the observed biological activities of the parent molecules. This communication delineates the development of a divergent strategy to furnish melazolide B and several other related congeners from a common keto-lactone intermediate, which was rapidly assembled from α-ionone. A chemoselective carbonyl α,β-dehydrogenation and a Wharton reduction were key strategic steps in this synthetic pathway.
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Affiliation(s)
| | | | - Yizhou Zhao
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
| | - Jaehoo Lee
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT, 06520-8107, United States
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Abstract
Conjugated dienes are versatile building blocks and prevalent substructures in synthetic chemistry. Herein, we report a method for the stereoselective hydroalkenylation of alkynes, utilizing readily available enol triflates. We leveraged an in situ-generated and geometrically pure vinyl-Cu(I) species to form the Z,Z- or Z,E-1,3-dienes in excellent stereoselectivity and yield. This approach allowed for the synthesis of highly substituted Z-dienes, including pentasubstituted 1,3-dienes, which are difficult to prepare by existing approaches.
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Affiliation(s)
- Chuan-Jin Hou
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander W Schuppe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - James Levi Knippel
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Anton Z Ni
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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Schuppe AW, Knippel JL, Borrajo-Calleja GM, Buchwald SL. Enantioselective Hydroalkenylation of Olefins with Enol Sulfonates Enabled by Dual Copper Hydride and Palladium Catalysis. J Am Chem Soc 2021; 143:5330-5335. [PMID: 33784090 DOI: 10.1021/jacs.1c02117] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The catalytic enantioselective synthesis of α-chiral olefins represents a valuable strategy for rapid generation of structural diversity in divergent syntheses of complex targets. Herein, we report a protocol for the dual CuH- and Pd-catalyzed asymmetric Markovnikov hydroalkenylation of vinyl arenes and the anti-Markovnikov hydroalkenylation of unactivated olefins, in which readily available enol triflates can be utilized as alkenyl coupling partners. This method allowed for the synthesis of diverse α-chiral olefins, including tri- and tetrasubstituted olefin products, which are challenging to prepare by existing approaches.
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Affiliation(s)
- Alexander W Schuppe
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - James Levi Knippel
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Gustavo M Borrajo-Calleja
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Schuppe AW, Liu Y, Newhouse TR. An invocation for computational evaluation of isomerization transforms: cationic skeletal reorganizations as a case study. Nat Prod Rep 2021; 38:510-527. [PMID: 32931541 PMCID: PMC7956923 DOI: 10.1039/d0np00005a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Covering: 2010 to 2020This review article describes how cationic rearrangement reactions have been used in natural product total synthesis over the last decade as a case study for the many productive ways by which isomerization reactions are enabling for synthesis. This review argues that isomerization reactions in particular are well suited for computational evaluation, as relatively simple calculations can provide significant insight.
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Affiliation(s)
- Alexander W Schuppe
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06511-8107, USA.
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10
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Abstract
An improved protocol for the Pd-catalyzed C-O cross-coupling of secondary alcohols is described. The use of biaryl phosphine L2 as the ligand was key to achieving efficient cross-coupling of (hetero)aryl chlorides with only a 20% molar excess of the alcohol. Additionally, we observed an unusual reactivity difference between an electron-rich aryl bromide and the analogous aryl chloride, and deuterium-labeling suggested that currently unidentified pathways for reduction play an important role in explaining this disparity.
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Affiliation(s)
- Hong Zhang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Paula Ruiz-Castillo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Alexander W Schuppe
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Stephen L Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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11
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Abstract
The enantioselective hydrocyanation of olefins represents a conceptually straightforward approach to prepare enantiomerically enriched nitriles. These, in turn, comprise or are intermediates in the synthesis of many pharmaceuticals and their synthetic derivatives. Herein, we report a cyanide-free dual Pd/CuH-catalyzed protocol for the asymmetric Markovnikov hydrocyanation of vinyl arenes and the anti-Markovnikov hydrocyanation of terminal olefins in which oxazoles function as nitrile equivalents. After an initial hydroarylation process, the oxazole substructure was deconstructed using a [4 + 2]/retro-[4 + 2] sequence to afford the enantioenriched nitrile product under mild reaction conditions.
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Affiliation(s)
| | | | - Stephen L. Buchwald
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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12
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Schuppe AW, Zhao Y, Liu Y, Newhouse TR. Total Synthesis of (+)-Granatumine A and Related Bislactone Limonoid Alkaloids via a Pyran to Pyridine Interconversion. J Am Chem Soc 2019; 141:9191-9196. [PMID: 31117671 DOI: 10.1021/jacs.9b04508] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report the first total synthesis of (+)-granatumine A, a limonoid alkaloid with PTP1B inhibitory activity, in ten steps. Over the course of this study, two key methodological advances were made: a cost-effective procedure for ketone α,β-dehydrogenation using allyl-Pd catalysis, and a Pd-catalyzed protocol to convert epoxyketones to 1,3-diketones. The central tetrasubstituted pyridine is formed by a convergent Knoevenagel condensation and carbonyl-selective electrocyclization cascade, which was followed by a direct transformation of a 2 H-pyran to a pyridine. These studies have led to the structural revision of two members of this family.
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Affiliation(s)
- Alexander W Schuppe
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Yizhou Zhao
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Yannan Liu
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
| | - Timothy R Newhouse
- Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520-8107 , United States
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Zhang HJ, Schuppe AW, Pan ST, Chen JX, Wang BR, Newhouse TR, Yin L. Copper-Catalyzed Vinylogous Aerobic Oxidation of Unsaturated Compounds with Air. J Am Chem Soc 2018; 140:5300-5310. [DOI: 10.1021/jacs.8b01886] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Hai-Jun Zhang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Alexander W. Schuppe
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Shi-Tao Pan
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Jin-Xiang Chen
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Bo-Ran Wang
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Liang Yin
- CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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Schuppe AW, Huang D, Chen Y, Newhouse TR. Total Synthesis of (-)-Xylogranatopyridine B via a Palladium-Catalyzed Oxidative Stannylation of Enones. J Am Chem Soc 2018; 140:2062-2066. [PMID: 29338207 DOI: 10.1021/jacs.7b13189] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We report a total synthesis of the pyridine-containing limonoid alkaloid (-)-xylogranatopyridine B in 11 steps from commercially available dihydrocarvone. The central pyridine ring was assembled by a late-stage fragment coupling approach employing a modified Liebeskind pyridine synthesis. One fragment was prepared by an allyl-palladium catalyzed oxidative enone β-stannylation, in which the key bimetallic β-stannyl palladium enolate intermediate undergoes a β-hydride elimination. This methodology also allowed introduction of alkyl and silyl groups to the β-position of enones.
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Affiliation(s)
- Alexander W Schuppe
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - David Huang
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Yifeng Chen
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Timothy R Newhouse
- Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
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Schuppe AW, Newhouse TR. Assembly of the Limonoid Architecture by a Divergent Approach: Total Synthesis of (±)-Andirolide N via (±)-8α-Hydroxycarapin. J Am Chem Soc 2017; 139:631-634. [PMID: 28001380 PMCID: PMC5928519 DOI: 10.1021/jacs.6b12268] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We report the first total synthesis of the limonoid andirolide N using a 12-step sequence from commercially available materials. The final step of this route demonstrates the chemical feasibility of our biosynthetic proposal that andirolide N arises from 8α-hydroxycarapin. The strategic use of a degraded limonoid as a platform for the synthesis of more structurally complex congeners may be a general approach to obtain limonoids with diverse functional properties.
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Affiliation(s)
- Alexander W. Schuppe
- Department of Chemistry, Yale University, 275 Prospect Street, New Haven, Connecticut 06520-8107, United States
| | - Timothy R. Newhouse
- Department of Chemistry, Yale University, 275 Prospect Street, New Haven, Connecticut 06520-8107, United States
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16
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Huang D, Schuppe AW, Liang MZ, Newhouse TR. Scalable procedure for the fragmentation of hydroperoxides mediated by copper and iron tetrafluoroborate salts. Org Biomol Chem 2016; 14:6197-200. [PMID: 27273761 DOI: 10.1039/c6ob00941g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An improved protocol for the formal elimination of propene from organic substrates is reported. This process entails the ozonolytic conversion of an alkene to a methoxy hydroperoxide which undergoes fragmentation mediated by copper and iron. The use of soluble Cu(BF4)2 and Fe(BF4)2 results in reproducible results up to a 100 gram scale.
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Affiliation(s)
- David Huang
- Department of Chemistry, Yale University, 275 Prospect St., New Haven, CT 06520-8107, USA.
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