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Wang J, Huo A, Li X, Li Y, Zhang Y, Jin T, Sun K, Yang J. Synthesis of Unnatural α-Amino Acids from (Pyridin-2-yl) Carbamate via CIPE-Induced Carbonyl Migration. J Org Chem 2022; 87:13615-13626. [PMID: 36263722 DOI: 10.1021/acs.joc.2c01283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Synthetic methods of unnatural α-amino acids have always been the focus of extensive research due to their significant bioactivities. However, convenient transition-metal-free catalyzed methods are still in demand. Herein, we report a novel strategy for the construction of an unnatural α-amino acid skeleton via intramolecular rearrangement of carbamates, which are readily available from amines and their common protecting groups. This rearrangement could afford a variety of amino ester products in up to 98% yield, even in gram-scale reaction. The reaction mechanism was studied in detail through experiments and theoretical calculations. The complex-induced proximity effect (CIPE) from the 2-pyridyl group is shown to be indispensable for this transformation.
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Affiliation(s)
- Juhui Wang
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Aiwen Huo
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Xiang Li
- Qinhuangdao Customs Technical Center, Qinhuangdao 066004, P. R. China
| | - Yue Li
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Yan Zhang
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Tengda Jin
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Keju Sun
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
| | - Jingyue Yang
- State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Nano-Biotechnology, Yanshan University, Qinhuangdao 066004, P. R. China
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Further Studies on the [1,2]-Wittig Rearrangement of 2-(2-Benzyloxy)aryloxazolines. Molecules 2022; 27:molecules27103186. [PMID: 35630665 PMCID: PMC9144599 DOI: 10.3390/molecules27103186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/10/2022] [Accepted: 05/13/2022] [Indexed: 11/16/2022] Open
Abstract
The behaviour of 14 ortho-functionalised 2-aryloxazolines (11 of them prepared and characterised for the first time) with butyllithium has been examined. Significant limitations to the Wittig rearrangement of such systems are revealed. In terms of asymmetric Wittig rearrangement, good diastereoselectivity is obtained with a valine-derived 4-isopropyl oxazoline, but this is compromised by racemisation upon hydrolysis. More encouraging selectivity is achieved in the Wittig rearrangement of an acyclic phenylalanine-derived ortho-benzyloxy benzamide.
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Aitken RA, Harper AD, Inwood RA, Slawin AMZ. Access to Diarylmethanols by Wittig Rearrangement of ortho-, meta-, and para-Benzyloxy- N-Butylbenzamides. J Org Chem 2022; 87:4692-4701. [PMID: 35286089 PMCID: PMC9007461 DOI: 10.1021/acs.joc.1c03160] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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The N-butyl amide
group, CONHBu, has been found
to be an effective promoter of the [1,2]-Wittig rearrangement of aryl
benzyl ethers and thus allow the two-step synthesis of isomerically
pure substituted diarylmethanols starting from simple hydroxybenzoic
acid derivatives. The method is compatible with a wide range of functional
groups including methyl, methoxy, and fluoro, although not with nitro
and, unexpectedly, is applicable to meta as well
as ortho and para isomeric series.
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Affiliation(s)
- R Alan Aitken
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
| | - Andrew D Harper
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
| | - Ryan A Inwood
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
| | - Alexandra M Z Slawin
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
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Ho GM, Li YJ. Tandem [1,2]-Wittig Rearrangement/Lactonization of γ-Benzyloxy Vinylogous Urethanes: Application to the Synthetic Studies of Maculalactone A, Planchol C and γ-Lycorane. ASIAN J ORG CHEM 2017. [DOI: 10.1002/ajoc.201700589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Guo-Ming Ho
- Department of Applied Chemistry; National Chiayi University; 300 Syuefu Road Chiayi City 60004 Taiwan
- Genomics Research Center; Academia Sinica; 128 Academia Road, Section 2 Taipei 11529 Taiwan
| | - Yu-Jang Li
- Department of Applied Chemistry; National Chiayi University; 300 Syuefu Road Chiayi City 60004 Taiwan
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Velasco R, Silva López C, Nieto Faza O, Sanz R. Exploring the Reactivity of α-Lithiated Aryl Benzyl Ethers: Inhibition of the [1,2]-Wittig Rearrangement and the Mechanistic Proposal Revisited. Chemistry 2016; 22:15058-15068. [DOI: 10.1002/chem.201602254] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 07/11/2016] [Indexed: 11/10/2022]
Affiliation(s)
- Rocío Velasco
- Área de Química Orgánica, Departamento de Química; Facultad de Ciencias; Universidad de Burgos; Pza. Misael Bañuelos s/n 09001 Burgos Spain
| | - Carlos Silva López
- Departamento de Química Orgánica; Universidade de Vigo; Campus As Lagoas 32004- Ourense Galicia Spain
| | - Olalla Nieto Faza
- Departamento de Química Orgánica; Universidade de Vigo; Campus As Lagoas 32004- Ourense Galicia Spain
| | - Roberto Sanz
- Área de Química Orgánica, Departamento de Química; Facultad de Ciencias; Universidad de Burgos; Pza. Misael Bañuelos s/n 09001 Burgos Spain
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Gao F, Kim BS, Walsh PJ. Chemoselective Palladium-Catalyzed Deprotonative Arylation/[1,2]-Wittig Rearrangement of Pyridylmethyl Ethers. Chem Sci 2016; 7:976-983. [PMID: 27014434 PMCID: PMC4800319 DOI: 10.1039/c5sc02739j] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 10/26/2015] [Indexed: 12/16/2022] Open
Abstract
Control of chemoselectivity is one of the most challenging problems facing chemists and is particularly important in the synthesis of bioactive compounds and medications. Herein, the first highly chemoselective tandem C(sp3)-H arylation/[1,2]-Wittig rearrangement of pyridylmethyl ethers is presented. The efficient and operationally simple protocols enable generation of either arylation products or tandem arylation/[1,2]-Wittig rearrangement products with remarkable selectivity and good to excellent yields (60-99%). Choice of base, solvent, and reaction temperature play a pivotal role in tuning the reactivity of intermediates and controlling the relative rates of competing processes. The novel arylation step is catalyzed by a Pd(OAc)2/NIXANTPHOS-based system via a deprotonative cross-coupling process. The method provides rapid access to skeletally diverse aryl(pyridyl)methanol core structures, which are central components of several medications.
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Affiliation(s)
- Feng Gao
- Department of Medicinal Plants , Agronomy College , Sichuan Agricultural University , 211, Huimin Rd, Wenjiang Region , Chengdu 611130 , PR China
- Roy and Diana Vagelos Laboratories , Penn/Merck Laboratory for High-Throughput Experimentation , Department of Chemistry , University of Pennsylvania , 231 S, 34th St. , Philadelphia , PA 19104-6323 , USA . ; https://sites.google.com/site/titaniumupenn/ ; Fax: +1-215-573-6743
| | - Byeong-Seon Kim
- Roy and Diana Vagelos Laboratories , Penn/Merck Laboratory for High-Throughput Experimentation , Department of Chemistry , University of Pennsylvania , 231 S, 34th St. , Philadelphia , PA 19104-6323 , USA . ; https://sites.google.com/site/titaniumupenn/ ; Fax: +1-215-573-6743
| | - Patrick J. Walsh
- Roy and Diana Vagelos Laboratories , Penn/Merck Laboratory for High-Throughput Experimentation , Department of Chemistry , University of Pennsylvania , 231 S, 34th St. , Philadelphia , PA 19104-6323 , USA . ; https://sites.google.com/site/titaniumupenn/ ; Fax: +1-215-573-6743
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Gao G, Gu FL, Jiang JX, Jiang K, Sheng CQ, Lai GQ, Xu LW. Neighboring Lithium-Assisted [1,2]-Wittig Rearrangement: Practical Access to Diarylmethanol-Based 1,4-Diols and Optically Active BINOL Derivatives with Axial and sp3-Central Chirality. Chemistry 2011; 17:2698-703. [DOI: 10.1002/chem.201003111] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Indexed: 11/08/2022]
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Li YJ, Lee PT, Yang CM, Chang YK, Weng YC, Liu YH. [2,3]-Wittig rearrangement of methyl β-pyrrolidinyl-γ-allyloxy-(E)-2-butenoate. Expeditious synthesis of 5-alkenyl-4-pyrrolidin-1-yl-5H-furan-2-ones. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lemiègre L, Regnier T, Combret JC, Maddaluno J. Conjugated elimination versus [1,2]-Wittig rearrangement of unsaturated diox(ol)anes. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(02)02568-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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