Carbon–carbon bond-forming reactions of α-carbonyl carbocations: exploration of a reversed-polarity equivalent of enolate chemistry
作者:Ping-Shan Lai、Joshua A. Dubland、Mohammed G. Sarwar、Michael G. Chudzinski、Mark S. Taylor
DOI:10.1016/j.tet.2011.07.065
日期:2011.9
Carbon–carbon bond-forming reactions of putative α-carbonyl carbocation intermediates generated by Lewis acid- or silver-promoted ionizations of toluenesulfonate or halide leaving groups are described. This under-exploited mode of reactivity represents an ‘umpolung’ of conventional enolate chemistry, and enables C–C bond construction in both intra- and intermolecular contexts. Attempts to develop diastereoselective
描述了由路易斯酸或银促进的甲苯磺酸盐或卤化物离去基团的电离产生的推定的α-羰基碳正离子中间体的碳-碳键形成反应。这种未充分利用的反应方式代表了常规烯醇式化学的“发展”,并在分子内和分子间环境下实现了C–C键的构建。讨论了尝试使用手性酯和基于恶唑烷酮的助剂开发该方法的非对映选择性变体的尝试。