General and Efficient Insertions of Carbons Carrying Aryl and Heteroaryl Groups: Synthesis of α-Aryl- and α-Heteroaryl-Substituted Ketones
作者:Alan R. Katritzky、Dorin Toader、Linghong Xie
DOI:10.1021/jo960841h
日期:1996.1.1
iazoles 1 with n-BuLi underwent addition to aliphatic and aromatic aldehydes and cyclic and acyclic ketones. Subsequent in situ thermal rearrangements of the intermediates in the presence of zinc bromide provided one-carbon chain-extended or ring-expanded alpha-aryl- and alpha-heteroaryl-substituted ketones 2 in moderate to excellent yields in simple one-pot operations with excellent regioselectivity
由多种1-(芳基甲基)-和1-(杂芳基甲基)苯并三唑1与正丁基锂的锂化反应所形成的阴离子要加入脂族和芳族醛以及环状和非环状酮中。中间体在溴化锌存在下的随后原位热重排可在简单的一锅操作中以中等至优异的产率提供一碳链扩展或环扩展的α-芳基-和α-杂芳基取代的酮2在大多数情况下具有区域选择性。在1-(4-甲氧基苄基)苯并三唑(1e)与XC(6)H(4)COPh的插入反应中研究了取代基对相对迁移速率的影响。较小的负Hammett rho(+)值(-0.92)表明,重排通过早期的,类似试剂的电子不足的过渡态进行。