Tandem Carbon Carbon Bond Forming Reaction via Zincate Carbenid

通过锌酸盐卡贝尼德进行串联碳碳键形成反应

• 批准号: 02650626
• 负责人: HARADA Toshiro
• 金额: $ 1.02万
• 依托单位: Kyoto Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650626/
• 关键词: Carbenoid; Zincate; Halogen; metal; exchange; Coupling Reaction; Palladium Catalyst

The electrophilic character of carbenoids as a-metallated carbocation equivalents has not been fully demonstrated in contrast to their widely studied nucleophilic nature. In the present study, we disclosed that lithium(1bromoalkenyl)(dialkyl)zincate and lithium(1-bromocyclopropyl)(dialkyl)-zincate which can be generated by a Br/Zn exchange reaction of the corresponding gem-dibromo compounds undergo a facile intramolecular alkylation reaction to give alkenyl- and cyclopropylzinc species. Since the resulting organozinc intermediates have potential of undergoing further C-C bond formation, the reaction was extended to the tandem substitution reaction of gem-dibromo compounds via Pd(O)catalyzed arylation, acylation and alkenylation reaction.

与广泛研究的亲核性质相比，类胡萝卜素作为α-金属化碳阳离子当量的亲电特性尚未得到充分证明。在本研究中，我们发现（1-溴代烯基）（二烷基）锌酸锂和（1-溴环丙基）（二烷基）锌酸锂可以通过相应偕二溴化合物的 Br/Zn 交换反应生成，并进行简单的分子内反应。烷基化反应得到烯基和环丙基锌物质。由于所得有机锌中间体有可能进一步形成C-C键，因此该反应通过Pd(O)催化的芳基化、酰化和烯基化反应扩展到偕二溴化合物的串联取代反应。