1
|
Babcock DJ, Wolfram AJ, Barney JL, Servagno SM, Sharma A, Nacsa ED. A free-radical design featuring an intramolecular migration for a synthetically versatile alkyl-(hetero)arylation of simple olefins. Chem Sci 2024; 15:4031-4040. [PMID: 38487219 PMCID: PMC10935719 DOI: 10.1039/d3sc06476j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/01/2023] [Accepted: 02/02/2024] [Indexed: 03/17/2024] Open
Abstract
A free-radical approach has enabled the development of a synthetically versatile alkyl-(hetero)arylation of olefins. Alkyl and (hetero)aryl groups were added concurrently to a full suite of mono- to tetrasubstituted simple alkenes (i.e., without requiring directing or electronically activating groups) for the first time. Key advances also included the introduction of synthetically diversifiable alkyl groups featuring different degrees of substitution, good diastereocontrol in both cyclic and acyclic settings, the addition of biologically valuable heteroarenes featuring Lewis basic nitrogen atoms as well as simple benzenes, and the generation of either tertiary or quaternary benzylic centers. The synthetic potential of this transformation was demonstrated by leveraging it as the key step in a concise synthesis of oliceridine, a new painkiller that received FDA approval in 2020.
Collapse
Affiliation(s)
- Dylan J Babcock
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| | - Andrew J Wolfram
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| | - Jaxon L Barney
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| | - Santino M Servagno
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| | - Ayush Sharma
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| | - Eric D Nacsa
- The Pennsylvania State University, Department of Chemistry University Park PA 16802 USA
| |
Collapse
|
2
|
Liu J, Hong Y, Liu YL, Tan JY, Liu HM, Dai GL, Chen SL, Liu T, Li JH, Tang S. Nickel-Catalyzed Radical Heck-Type C(sp 3)–C(sp 2) Coupling Cascades Enabled by Bromoalkane-Directed 1,4-Aryl Shift: Access to Olefinated Arylalanines. Org Lett 2022; 24:8192-8196. [DOI: 10.1021/acs.orglett.2c03250] [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: 11/13/2022]
Affiliation(s)
- Jian Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Yu Hong
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Yin-Ling Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Jing-Ying Tan
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Hao-Miao Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Gang-Liang Dai
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Institute of Technology, Beijing 100081, China
| | - Ting Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| | - Jin-Heng Li
- State Key Laboratory Base of Eco-Chemical Engineering, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Shi Tang
- College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, China
| |
Collapse
|
3
|
Keum H, Jung H, Jeong J, Kim D, Chang S. Visible‐Light Induced C(sp
2
)−H Amidation with an Aryl–Alkyl σ‐Bond Relocation via Redox‐Neutral Radical–Polar Crossover. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hyeyun Keum
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Hoimin Jung
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Jiwoo Jeong
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Dongwook Kim
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Sukbok Chang
- Department of Chemistry Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| |
Collapse
|
4
|
Keum H, Jung H, Jeong J, Kim D, Chang S. Visible-Light Induced C(sp 2 )-H Amidation with an Aryl-Alkyl σ-Bond Relocation via Redox-Neutral Radical-Polar Crossover. Angew Chem Int Ed Engl 2021; 60:25235-25240. [PMID: 34558167 DOI: 10.1002/anie.202108775] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [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: 07/01/2021] [Revised: 09/08/2021] [Indexed: 01/15/2023]
Abstract
We report an approach for the intramolecular C(sp2 )-H amidation of N-acyloxyamides under photoredox conditions to produce δ-benzolactams with an aryl-alkyl σ-bond relocation. Computational studies on the designed reductive single electron transfer strategy led us to identify N-[3,5-bis(trifluoromethyl)benzoyl] group as the most effective amidyl radical precursor. Upon the formation of an azaspirocyclic radical intermediate by the selective ipso-addition with outcompeting an ortho-attack, radical-polar crossover was then rationalized to lead to the rearomative ring-expansion with preferential C-C bond migration.
Collapse
Affiliation(s)
- Hyeyun Keum
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Hoimin Jung
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Jiwoo Jeong
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Dongwook Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| | - Sukbok Chang
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.,Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS), Daejeon, 34141, Republic of Korea
| |
Collapse
|
5
|
Abstract
![]()
The silyl-Prins cyclization of geminal
vinylsilyl alcohols and
aldehydes, promoted by TMSOTf, provides access to polysubstituted
tetrahydropyrans in which the silyl group remains in the molecule
and an aryl group has migrated from silicon to carbon. This domino
silyl-Prins/aryl migration process is general and high-yielding for
aryl, vinyl, or alkyl aldehydes. Moreover, cyclization proceeds with
very high stereocontrol in a one-pot reaction in which both quaternary
and tertiary stereogenic centers have been created.
Collapse
Affiliation(s)
- Carlos Díez-Poza
- Department of Organic Chemistry, Faculty of Sciences, University of Valladolid, Campus Miguel Delibes, Paseo de Belén 7, 47011 Valladolid, Spain
| | - Asunción Barbero
- Department of Organic Chemistry, Faculty of Sciences, University of Valladolid, Campus Miguel Delibes, Paseo de Belén 7, 47011 Valladolid, Spain
| |
Collapse
|
6
|
Tang S, Xu ZH, Liu T, Wang SW, Yu J, Liu J, Hong Y, Chen SL, He J, Li JH. Radical 1,4-Aryl Migration Enabled Remote Cross-Electrophile Coupling of α-Amino-β-Bromo Acid Esters with Aryl Bromides. Angew Chem Int Ed Engl 2021; 60:21360-21367. [PMID: 34291545 DOI: 10.1002/anie.202106273] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 05/10/2021] [Revised: 06/30/2021] [Indexed: 12/14/2022]
Abstract
We report an unprecedented, efficient nickel-catalysed radical relay for the remote cross-electrophile coupling of β-bromo-α-benzylamino acid esters with aryl bromides via 1,4-aryl migration/arylation cascades. β-Bromo-α-benzylamino acid esters are considered as unique molecular scaffolds allowing for aryl migration reactions, which are conceptually novel variants for the radical Truce-Smiles rearrangement. This reaction enables the formation of two new C(sp3 )-C(sp2 ) bonds using a bench-stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox-neutral C(sp3 )-C(sp2 ) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalytic cycles consisting of a cross-electrophile coupling and radical 1,4-aryl migration through the generation of C(sp3 )-centred radical intermediates from the homolysis of C(sp3 )-Br bonds and the switching of the transient alkyl radical into a robust α-aminoalkyl radical.
Collapse
Affiliation(s)
- Shi Tang
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Zhen-Hua Xu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Ting Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Shuo-Wen Wang
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Jian Yu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Jian Liu
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Yu Hong
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Shi-Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Institute of Technology, Beijing, 100081, China
| | - Jin He
- College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000, China
| | - Jin-Heng Li
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China.,State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082, China
| |
Collapse
|
7
|
Tang S, Xu Z, Liu T, Wang S, Yu J, Liu J, Hong Y, Chen S, He J, Li J. Radical 1,4‐Aryl Migration Enabled Remote Cross‐Electrophile Coupling of α‐Amino‐β‐Bromo Acid Esters with Aryl Bromides. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Shi Tang
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Zhen‐Hua Xu
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Ting Liu
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Shuo‐Wen Wang
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Jian Yu
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Jian Liu
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Yu Hong
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Shi‐Lu Chen
- Key Laboratory of Cluster Science of Ministry of Education Beijing Institute of Technology Beijing 100081 China
| | - Jin He
- College of Chemistry and Chemical Engineering Jishou University Jishou 416000 China
| | - Jin‐Heng Li
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle Nanchang Hangkong University Nanchang 330063 China
- State Key Laboratory of Chemo/Biosensing and Chemometrics Hunan University Changsha 410082 China
| |
Collapse
|
8
|
Guo C, Chen D, Chen S, Liu X. Synthesis of Tetrasubstituted α,β‐Unsaturated Aldehydes
via
Radical 1,4‐Aryl Migration/Trifluoromethylthiolation Cascade Reaction of Aryl Propynyl Ethers. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201700534] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Chun‐Huan Guo
- State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 People's Republic of China
| | - Dao‐Qian Chen
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 People's Republic of China
| | - Si Chen
- State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 People's Republic of China
| | - Xue‐Yuan Liu
- State Key Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 730000 People's Republic of China
| |
Collapse
|
9
|
Li L, Gu QS, Wang N, Song P, Li ZL, Li XH, Wang FL, Liu XY. 1,2-Difunctionalization-type (hetero)arylation of unactivated alkenes triggered by radical addition/remote (hetero)aryl migration. Chem Commun (Camb) 2017; 53:4038-4041. [DOI: 10.1039/c6cc09215b] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [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
A novel (hetero)arylation of unactivated alkenes has been developed via 1,4(5)-(hetero)aryl migration triggered by radical alkene azidation, trifluoromethylation, or phosphonylation.
Collapse
Affiliation(s)
- Lei Li
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Qiang-Shuai Gu
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Na Wang
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Ping Song
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Zhong-Liang Li
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Xiao-Hua Li
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Fu-Li Wang
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| | - Xin-Yuan Liu
- Department of Chemistry
- South University of Science and Technology of China
- Shenzhen
- China
| |
Collapse
|
10
|
Li L, Li ZL, Wang FL, Guo Z, Cheng YF, Wang N, Dong XW, Fang C, Liu J, Hou C, Tan B, Liu XY. Radical aryl migration enables diversity-oriented synthesis of structurally diverse medium/macro- or bridged-rings. Nat Commun 2016; 7:13852. [PMID: 28004746 DOI: 10.1038/ncomms13852] [Citation(s) in RCA: 130] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 11/04/2016] [Indexed: 12/13/2022] Open
Abstract
Medium-sized and medium-bridged rings are attractive structural motifs in natural products and therapeutic agents. Due to the unfavourable entropic and/or enthalpic factors with these ring systems, their efficient construction remains a formidable challenge. To address this problem, we herein disclose a radical-based approach for diversity-oriented synthesis of various benzannulated carbon- and heteroatom-containing 8–11(14)-membered ketone libraries. This strategy involves 1,4- or 1,5-aryl migration triggered by radical azidation, trifluoromethylation, phosphonylation, sulfonylation, or perfluoroalkylation of unactivated alkenes followed by intramolecular ring expansion. Demonstration of this method as a highly flexible tool for the construction of 37 synthetically challenging medium-sized and macrocyclic ring scaffolds including bridged rings with diverse functionalities and skeletons is highlighted. Some of these products showed potent inhibitory activity against the cancer cell or derivative of human embryonic kidney line in preliminary biological studies. The mechanism of this novel strategy is investigated by control experiments and DFT calculations. Medium-sized ring systems are common in natural products, however their synthesis is challenging, largely due to entropic factors. Here the authors report a radical-based method for the synthesis of medium to large functionalized, carbon or heterocyclic scaffolds.
Collapse
|
11
|
Abstract
Hydrogen atom transfer (HAT) circumvents a disfavored Friedel-Crafts reaction in the derivatization of the inexpensive monoterpene isopulegol. A variety of readily prepared aryl and heteroaryl sulfonates undergo a formal hydroarylation to form 8-arylmenthols, privileged scaffolds for asymmetric synthesis, as typified by 8-phenylmenthol. High stereoselectivity is observed in related systems. This use of HAT significantly extends the chiral pool from the inexpensive monoterpene isopulegol.
Collapse
Affiliation(s)
- Steven W M Crossley
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Ruben M Martinez
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Sebastián Guevara-Zuluaga
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Ryan A Shenvi
- Department of Chemistry, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| |
Collapse
|
12
|
Ujjainwalla F, da Mata MLE, Pennell AM, Escolano C, Motherwell WB, Vázquez S. Synthesis of biaryls via intramolecular free radical ipso-substitution reactions. Tetrahedron 2015. [DOI: 10.1016/j.tet.2015.07.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
13
|
Wu P, Wang L, Wu K, Yu Z. Brønsted Acid Catalyzed PhSe Transfer versus Radical Aryl Transfer: Linear Codimerization of Styrenes and Internal Olefins. Org Lett 2015; 17:868-71. [DOI: 10.1021/ol503731s] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Ping Wu
- Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan
Road, Dalian 116023, P. R. China
| | - Liandi Wang
- Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan
Road, Dalian 116023, P. R. China
| | - Kaikai Wu
- Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan
Road, Dalian 116023, P. R. China
| | - Zhengkun Yu
- Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan
Road, Dalian 116023, P. R. China
- State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, P. R. China
| |
Collapse
|
14
|
Abstract
This review provides a comprehensive summary of radical aryl migration reactions, highlighting their mechanistic studies and synthetic applications.
Collapse
Affiliation(s)
- Zhi-Min Chen
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- P. R. China
| | - Xiao-Ming Zhang
- State Key Laboratory of Applied Organic Chemistry
- Lanzhou University
- Collaborative Innovation Center of Chemical Science and Engineering
- Lanzhou
- Tianjin
| | - Yong-Qiang Tu
- School of Chemistry and Chemical Engineering
- Shanghai Jiao Tong University
- Shanghai 200240
- P. R. China
- State Key Laboratory of Applied Organic Chemistry
| |
Collapse
|
15
|
Wang C, Xie X, Liu J, Liu Y, Li Y. Gold(I)-Catalyzed 1,4- and/or 1,5-Heteroaryl Migration Reactions through Regiocontrolled Cyclizations. Chemistry 2014; 21:559-64. [DOI: 10.1002/chem.201405190] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Indexed: 11/10/2022]
|
16
|
Cinar ME, Vavilala C, Jaquet R, Bats JW, Schmittel M. Fluoro-Ene Reaction Versus [2+2] Cycloaddition in the Thermal C2-C6Cyclization of Enyne-Allenes: An Experimental and Theoretical Investigation. European J Org Chem 2014. [DOI: 10.1002/ejoc.201402438] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
17
|
Kothapalli RB, Niddana R, Balamurugan R. Synthesis of Chiral α-Diarylacetic Esters by Stereospecific 1,2-Aryl Migration Promoted by in Situ Generated Acetals from Benzoins. Org Lett 2014; 16:1278-81. [DOI: 10.1021/ol500292c] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Raveendra Babu Kothapalli
- School of Chemistry, University of Hyderabad, Dr. C. R. Rao Road, Gachibowli, Hyderabad 500046, India
| | - Ramana Niddana
- School of Chemistry, University of Hyderabad, Dr. C. R. Rao Road, Gachibowli, Hyderabad 500046, India
| | - Rengarajan Balamurugan
- School of Chemistry, University of Hyderabad, Dr. C. R. Rao Road, Gachibowli, Hyderabad 500046, India
| |
Collapse
|
18
|
Rouquet G, Robert F, Méreau R, Castet F, Renaud P, Landais Y. Silylboranes as new sources of silyl radicals for chain-transfer reactions. Chemistry 2012; 18:940-50. [PMID: 22180016 DOI: 10.1002/chem.201102318] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Indexed: 11/05/2022]
Abstract
Various silylboranes, which were outfitted with a catecholborane moiety at one end and a (Me(3)Si)(3)Si moiety at the other end of a carbon chain, were prepared through the hydroboration of the corresponding unsaturated silanes. The C-centered radical species generated from these silylboranes efficiently cyclized to provide, through a 5-exo intramolecular homolytic substitution at the silicon center, the corresponding silacycle and a Me(3)Si radical that was subsequently trapped by sulfonyl acceptors. These cyclizations proceeded at unprecedented rates, due, in part, to a strong gem-dialkyl effect that was attributable to the presence of bulky substituents on a quaternary center located on the chain. In parallel, we designed arylsilylboranes that produced silyl radicals through a 1,5-hydrogen transfer. Such silyl radicals may be valuable radical chain carriers, for instance, in oximation reactions of alkyl halides. Finally, computational studies allowed calculation of activation barriers of the homolytic substitution step and additionally illustrated that the overall reaction mechanism involved a transition state in which the attacking carbon center, the central silicon atom, and the Me(3)Si leaving group were collinear.
Collapse
Affiliation(s)
- Guy Rouquet
- Université de Bordeaux, Institut des Sciences Moléculaires, UMR-CNRS 5255, 351, Cours de la libération 33405 Talence Cedex, France
| | | | | | | | | | | |
Collapse
|
19
|
Pratsch G, Heinrich MR. Modern Developments in Aryl Radical Chemistry. In: Heinrich M, Gansäuer A, editors. Radicals in Synthesis III. Berlin: Springer Berlin Heidelberg; 2012. pp. 33-59. [DOI: 10.1007/128_2011_127] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
20
|
Affiliation(s)
- Raphaël Méreau
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| | - Philippe d’Antuono
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| | - Frédéric Castet
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| | - Guy Rouquet
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| | - Frédéric Robert
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| | - Yannick Landais
- Institut des Sciences Moléculaires, UMR-CNRS 5255, Université de Bordeaux, 351, Cours de la Libération, 33405 Talence, France
| |
Collapse
|
21
|
Wu L, Shi M, Li Y. BF3⋅OEt2-Catalyzed Intermolecular Reactions of Vinylidenecyclopropanes with Bis(p-alkoxyphenyl)methanols: A Novel Cationic 1,4-Aryl-Migration Process. Chemistry 2010; 16:5163-72. [DOI: 10.1002/chem.200903131] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
22
|
|
23
|
Robertson J, Palframan MJ, Shea SA, Tchabanenko K, Unsworth WP, Winters C. Radical 1,4-aryl transfer in arylcarboxamides leading to phthalimides, biaryls and enantiomerically enriched β-arylethylamines. Tetrahedron 2008; 64:11896-907. [DOI: 10.1016/j.tet.2008.07.118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
24
|
Gowrisankar S, Kim SJ, Lee JE, Kim JN. Unusual synthesis of dihydropyrido[2,1-a]isoindolone derivatives by radical cyclization of enamides of Baylis–Hillman adducts. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.04.111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
25
|
Abstract
Radical intermediates can undergo specific reactions, such as intramolecular rearrangements, i.e., the transpositions of radical centers, which are not known in classical ionic organic reactions. 1,5-Transposition of a radical center to a non-activated carbon atom are of great synthetic importance. It can be successfully applied for the introduction of different functional groups (oxygen, nitrogen, sulfur, halogens) onto a carbon atom remote from the present functional group. In addition to functionalization of a remote non-activated carbon atom, the formation of new C-C bonds on the ?-carbon atom have also been achieved. 1,5-Transposition of the radical centers takes place from alkoxyl, aminyl and carbon radicals to a remote carbon atom. Relocation of the radical centers preferentially involves 1,5-transfer of a hydrogen atom, although migrations of some other groups are known. The reactions of the carbon radical generated by 1,5-relocation of the radical center are presented and their synthetic applications are reviewed.
Collapse
|
26
|
Abstract
Samarium(II)-mediated spirocyclization onto an aromatic ring was achieved by the reaction of methyl 4-(4-oxoalkyl)benzoates with SmI(2) in the presence of i-PrOH and HMPA, yielding methyl 1-alkyl-1-hydroxyspiro[4.5]dec-6-ene-8-carboxylates in moderate to high yields. Utilizing this chemistry, spiro[3.5] and -[5.5] systems, and sterically congested spiro[4.5] systems, were easily synthesized. For the successful conversion, appropriate activation of the aromatic ring has proven to be extremely important: while an ester or amide functionality on the aromatic ring can promote the spirocyclization, a sulfonamide substituent causes ortho cyclization.
Collapse
Affiliation(s)
- Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | | | | | | | | | |
Collapse
|
27
|
Ohno H, Wakayama R, Maeda SI, Iwasaki H, Okumura M, Iwata C, Mikamiyama H, Tanaka T. Radical cyclization by ipso substitution of the methoxy group: considerable effect of HMPA on samarium-mediated cyclization. J Org Chem 2003; 68:5909-16. [PMID: 12868925 DOI: 10.1021/jo0343174] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [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
Alkyl radicals generated by treatment of thiocarbamates of conformationally favorable 3-alkyl-3-arylpropan-1-ols with tris(trimethylsilyl)silane and AIBN efficiently undergo intramolecular ipso substitution of the methoxy group, yielding the corresponding cyclized products. In contrast, either conformationally favorable or flexible 1-arylalkan-3- or 4-ones easily cyclize into five- or six-membered condensed rings by treatment with SmI(2) via ketyl radical intermediates. The addition of HMPA as cosolvent dramatically changes the cyclization mode of the SmI(2)-induced reaction, and the para-cyclization products are exclusively formed. This "HMPA effect" can be rationalized by the strong chelating ability of HMPA with the samarium atom.
Collapse
Affiliation(s)
- Hiroaki Ohno
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Zhang W, Pugh G. Free radical reactions for heterocycle synthesis. Part 6: 2-Bromobenzoic acids as building blocks in the construction of nitrogen heterocycles. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00381-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
29
|
|
30
|
|
31
|
Ryokawa A, Togo H. Synthetic use of 1,1,2,2-tetraphenyldisilane for the preparation of biaryls through the intramolecular free radical ipso-substitution of N-(2-bromoaryl)arenesulfonamides. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00560-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
32
|
|
33
|
Harrowven DC, Nunn MI, Newman NA, Fenwick DR. A new cascade radical reaction for the synthesis of biaryls and triaryls from benzyl iodoaryl ethers. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(00)02111-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|