Zhang L, Bao W, Liang Y, Pan W, Li D, Kong L, Wang ZX, Peng B. Morita-Baylis-Hillman-Type [3,3]-Rearrangement: Switching from Z- to E-Selective α-Arylation by New Rearrangement Partners.
Angew Chem Int Ed Engl 2021;
60:11414-11422. [PMID:
33644970 DOI:
10.1002/anie.202100497]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/25/2021] [Indexed: 01/03/2023]
Abstract
α-aryl α,β-unsaturated carbonyls represent an important class of derivatizable synthetic intermediates, however, the synthesis of such compounds still remains a challenge. Recently, we showcased a novel Z-selective α-arylation of α,β-unsaturated nitriles with aryl sulfoxides via [3,3]-rearrangement involving an Morita-Baylis-Hillman (MBH) process. Herein, we demonstrate the feasibility of reversing the stereoselectivity of such MBH-type [3,3]-rearrangement by switching to a new pair of rearrangement partners consisting of aryl iodanes and α,β-unsaturated oxazolines. As a result, the two protocols complement each other in approaching E- or Z-α-aryl α,β-unsaturated carbonyl derivatives. Mechanistic studies reveal a possible reaction pathway and provide an explanation for the opposite stereoselectivities.
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