Morita-Baylis-Hillman-Type 3,3 -Rearrangement: Switching from Z- to E-Selective alpha-Arylation by New Rearrangement Partners
Morita-Baylis-Hillman-Type 3,3 -Rearrangement: Switching from Z- to E-Selective alpha-Arylation by New Rearrangement Partners
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Morita-Baylis-Hillman-Type 3,3-重排：新重排伙伴将 Z- 选择性 α-芳基化转变为 E-选择性 α-芳基化
DOI：
10.1002/anie.202100497
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Peng Bo
中科院分区：
文献类型：
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作者：
Zhang Lei;Bao Wangzhen;Liang Yuchen;Pan Wenjing;Li Dongyang;Kong Lichun;Wang Zhi-Xiang;Peng Bo
α-芳基α，β-不饱和羰基化合物是一类重要的可衍生化合成中间体，但此类化合物的合成仍然是一个挑战。最近，我们展示了一种新颖的Z-选择性α-芳基化反应，通过[3，3]-重排反应使α，β-不饱和腈与芳基亚砜发生Z-选择性芳基化反应。在这里，我们证明了通过切换到由芳基碘烷和α，β-不饱和恶唑啉组成的新的重排对来逆转这种MBH型[3，3]-重排的立体选择性的可行性。因此，这两个方案在接近E-orz-α-芳基α，β-不饱和羰基衍生物方面相辅相成。机理研究揭示了一种可能的反应途径，并为相反的立体选择性提供了解释。
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 novelZ‐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 approachingE‐ orZ‐α‐aryl α,β‐unsaturated carbonyl derivatives. Mechanistic studies reveal a possible reaction pathway and provide an explanation for the opposite stereoselectivities.