摘要/Abstract

报道了一类由叔丁基自由基引发的1,2-炔基迁移反应. 该反应利用特戊醛在二叔丁基过氧化物(DTBP)介导下能产生叔丁基自由基的特性, 将其与1,4-烯炔底物发生自由基加成及炔基迁移过程, 合成了一系列α-炔基酮化合物, 产率优良, 实现了非活化烯烃的烷基炔基化. 基于实验结果及文献报道, 提出了可能的反应机理, 涉及叔丁基自由基激发的自由基加成、反“鲍德温”规则的3-exo-dig环化及炔基迁移过程. 该反应具有官能团兼容性高、无需金属催化剂及操作简便等优点, 为非活化烯烃的双官能团化提供了一种有效的策略.
关键词: 炔基迁移, 1,4-烯炔, 双官能团化, 反鲍德温规则
A new tert-butyl radical-induced 1,2-alkynyl migration reaction is reported. By using the characteristics of in-situ-generation of tert-butyl radical from pivalaldehyde mediated by di-tert-butyl peroxide (DTBP), tert-butyl radical-triggered addition and alkynyl migration of the preformed 1,4-enynes led to the synthesis of a series of α-alkynyl ketones with good to excellent yields, thereby realizing alkylalkynylation of unactivated olefins. Based on the experimental results and literature reports, a possible reaction mechanism is proposed, which involvestert-butyl radical-triggered addition, 3-exo-dig cyclization of anti-“Baldwin” rule and alkynyl migration process. This reaction has the advantages of high functional group compatibility, metal-free conditions, and simple operation, which provides a feasible and effective synthetic strategy for the bifunctionalization of unactivated olefins.
Key words: alkynyl migration, 1,4-enynes, bifunctionalization, anti-baldwin rule


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