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Pattanaik S, Kumar A, Gunanathan C. Cobalt-catalysed [1,2]-Wittig rearrangement of ethers to secondary alcohols. Chem Commun (Camb) 2023; 59:1853-1856. [PMID: 36722974 DOI: 10.1039/d2cc06937g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Stable ethers are successfully transformed into secondary alcohols via C-O bond activation using a simple cobalt pincer catalyst. Mechanistic studies indicate the involvement of radical pairs, and their sequential recombination and the subsequent hydrolysis results in the formation of secondary alcohols.
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Affiliation(s)
- Sandip Pattanaik
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar-752050, India.
| | - Anurag Kumar
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar-752050, India.
| | - Chidambaram Gunanathan
- School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar-752050, India.
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3
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Alam MN, K M L, Maity P. A removable functional group strategy for regiodivergent Wittig rearrangement products. Org Biomol Chem 2019; 16:8922-8926. [PMID: 30431052 DOI: 10.1039/c8ob02221f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
[1,2] and [2,3] Wittig rearrangements are competing reaction pathways, often leading to uncontrollable product distribution. We employ a single removable functional group to fulfill the dual role of attaining a reversible [2,3] and stabilizing radical intermediate for the [1,2] path to obtain both the Wittig products selectively for a broad range of substrates.
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Affiliation(s)
- Md Nirshad Alam
- Organic Chemistry Division, CSIR-National Chemical Laboratory, Pune-411008, India.
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4
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Nath SR, Joshi KA. Mechanistic investigation in the [1,4] and [1,2] Wittig rearrangement reactions: a DFT study. Phys Chem Chem Phys 2018; 20:21457-21473. [PMID: 30087956 DOI: 10.1039/c8cp01045e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The mechanistic pathways for the [1,4] and [1,2] Wittig rearrangements of 2-silyl-6-aryl-5,6-dihydro-(2H)-pyrans have been studied at the M06-2X/6-31+G(d,p), 6-311++G(d,p) and cc-pVTZ level of theory. The crucial C-O bond cleavage step in the mechanism has been analysed initially, using two model reactions covering aliphatic as well as cyclic allylic ethers. The barriers for the one-step as well as two-step pathways have been calculated and the mechanisms for both the [1,4] and [1,2] Wittig rearrangement reactions are predicted to occur through a two-step mode. An energetic analysis of the reaction pathways reveals that the [1,4]-rearrangement has a lower barrier than the [1,2]-Wittig rearrangement. The C-O cleavage transition state was found to have the highest barrier and is thus the rate determining transition state for all of the studied molecules. This is in agreement with the previously published experimental studies. The role of the allylic trimethylsilane group in the stabilization of the intermediate anions of the Wittig reactants has also been investigated while comparing it with the phenyl and allylic t-butyl groups through Natural Bond Orbital (NBO) calculations.
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Affiliation(s)
- Shilpa R Nath
- Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
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Liu Z, Li M, Wang B, Deng G, Chen W, Kim BS, Zhang H, Yang X, Walsh PJ. Chemoselective synthesis of aryl(pyridinyl)methanol derivatives through Ni-NIXANTPHOS catalyzed α-arylation and tandem arylation/rearrangement of pyridylmethyl ethers. Org Chem Front 2018. [DOI: 10.1039/c8qo00207j] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
An efficient synthesis of aryl(pyridyl)-methanol derivatives using Ni-NIXANTPHOS catalyzed α-arylation and tandem arylation/rearrangement is described.
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Affiliation(s)
- Zhengfen Liu
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Minyan Li
- Department of Chemistry
- Roy and Diana Vagelos Laboratories
- Penn/Merck Laboratory for High-Throughput Experimentation
- University of Pennsylvania
- Philadelphia
| | - Bijun Wang
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Guogang Deng
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Wen Chen
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Byeong-Seon Kim
- Department of Chemistry
- Roy and Diana Vagelos Laboratories
- Penn/Merck Laboratory for High-Throughput Experimentation
- University of Pennsylvania
- Philadelphia
| | - Hongbin Zhang
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Xiaodong Yang
- Key Laboratory of Medicinal Chemistry for Natural Resources
- Ministry of Education and Yunnan Province
- School of Chemical Science and Technology
- Yunnan University
- Kunming
| | - Patrick J. Walsh
- Department of Chemistry
- Roy and Diana Vagelos Laboratories
- Penn/Merck Laboratory for High-Throughput Experimentation
- University of Pennsylvania
- Philadelphia
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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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Tayama E, Kobayashi Y, Toma Y. Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino-N-Boc-enamines. Chem Commun (Camb) 2016; 52:10570-3. [PMID: 27498628 DOI: 10.1039/c6cc04626f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino-N-Boc-enamines was demonstrated.
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Affiliation(s)
- Eiji Tayama
- Department of Chemistry
- Faculty of Science
- Niigata University
- Niigata
- Japan
| | | | - Yuka Toma
- Department of Chemistry
- Faculty of Science
- Niigata University
- Niigata
- Japan
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Mori-Quiroz LM, Maleczka RE. Stereoconvergent [1,2]- and [1,4]-Wittig rearrangements of 2-silyl-6-aryl-5,6-dihydropyrans: a tale of steric vs electronic regiocontrol of divergent pathways. J Org Chem 2015; 80:1163-91. [PMID: 25490725 PMCID: PMC4301091 DOI: 10.1021/jo5026942] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 11/29/2022]
Abstract
The regiodivergent ring contraction of diastereomeric 2-silyl-5,6-dihydro-6-aryl-(2H)-pyrans via [1,2]- and [1,4]-Wittig rearrangements to the corresponding α-silylcyclopentenols or (α-cyclopropyl)acylsilanes favor the [1,4]-pathway by ortho and para directing groups in the aromatic appendage and/or by sterically demanding silyl groups. The [1,2]-pathway is dominant with meta directing or electron-poor aromatic moieties. Exclusive [1,2]-Wittig rearrangements are observed when olefin substituents proximal to the silyl are present. cis and trans diastereomers exhibit different reactivities, but converge to a single [1,2]- or [1,4]-Wittig product with high diastereoselectivity and yield.
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Affiliation(s)
- Luis M. Mori-Quiroz
- Department of Chemistry, Michigan
State University, 578
South Shaw Lane, East
Lansing, Michigan 48824, United States
| | - Robert E. Maleczka
- Department of Chemistry, Michigan
State University, 578
South Shaw Lane, East
Lansing, Michigan 48824, United States
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Onyeozili EN, Mori-Quiroz LM, Maleczka RE. [1,2]- and [1,4]-Wittig Rearrangements of α-Alkoxysilanes: Effect of Substitutions at both the Migrating Benzylic Carbon and the Terminal sp 2 Carbon of the Allyl Moiety. Tetrahedron 2013; 69:849-860. [PMID: 23459008 PMCID: PMC3580876 DOI: 10.1016/j.tet.2012.10.091] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Substituted α-alkoxysilanes can be deprotonated by alkyllithium bases and made to undergo Wittig rearrangements to afford the #x0005B;1,4]- and [1,2]-rearranged products in varying ratios. Substitution at the benzylic migrating carbon and/or at the allylic carbon of the allyl moiety impacts the rearrangement reaction, influencing the reactivity as well as the [1,4]-/[1,2]-selectivity. Diastereomeric α-alkoxysilanes show different reactivities with the syn diastereomer being the more reactive isomer.
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Affiliation(s)
- Edith N. Onyeozili
- Department of Chemistry, Florida A&M University, Tallahassee, FL 32307 USA
| | - Luis M. Mori-Quiroz
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI 48824 USA
| | - Robert E. Maleczka
- Department of Chemistry, Michigan State University, 578 S. Shaw Lane, East Lansing, MI 48824 USA
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Brekan JA, Chernyak D, White KL, Scheidt KA. Lewis base-promoted carbon–carbon sp3–sp3 coupling reactions of α-silyl silylethers. Chem Sci 2012. [DOI: 10.1039/c2sc00581f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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11
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Onyeozili EN, Maleczka RE. Studies on the deprotonation and subsequent [1,4]-Wittig rearrangement of α-benzyloxyallylsilanes. Tetrahedron Lett 2006. [DOI: 10.1016/j.tetlet.2006.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Onyeozili EN, Maleczka RE. alpha-Substituted acylsilanes via a highly selective [1,4]-Wittig rearrangement of alpha-benzyloxyallylsilane. Chem Commun (Camb) 2006:2466-8. [PMID: 16758017 DOI: 10.1039/b603228a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
alpha-Benzyloxyallylsilane undergoes efficient [1,4]-Wittig rearrangement to generate an enolate intermediate that can be trapped with various electrophiles, thereby providing a new synthetic approach to substituted acylsilanes.
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Affiliation(s)
- Edith N Onyeozili
- Department of Chemistry, Michigan State University, 540 Chemistry, East Lansing, Michigan 48824, USA
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R. Katritzky A, Fang Y. Benzotriazole-mediated [1,2]-Wittig Rearrangement. The Preparation of Homoalcohols from Ethers. HETEROCYCLES 2000. [DOI: 10.3987/com-00-8945] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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