Reaction of C-Silylated α-Diazophosphines as Nucleophiles toward Carbonyl Compounds: A Mechanistic Study and Application to the Synthesis of Alkynes and α-Hydroxyphosphonamides
作者:Ona Illa、Xavier Bagan、Anna M. Cazorla、Céline Lyon、Antoine Baceiredo、Vicenç Branchadell、Rosa M. Ortuño
DOI:10.1021/jo060663k
日期:2006.7.1
α-hydroxyphosphonamides and alkynes have been efficiently synthesized through the reaction of C-silylated α-diazophosphines with different types of aldehydes (2 equiv) in a neutral medium under very mild conditions. The reaction with some chiral aldehydes is highly diastereoselective leading to phosphonamides as single diastereomers. The novel reaction is influenced by electronic and steric effects being precluded for
在中性介质中,在非常温和的条件下,通过C甲硅烷基化的α-重氮膦与不同类型的醛(2当量)的反应,可以有效地合成不同取代的α-羟基膦酰胺和炔烃。与一些手性醛的反应是高度非对映选择性的,导致膦酰胺作为单一非对映异构体。对于在苯环上包含释放电子的取代基的芳族醛和大体积的脂族醛,排除了电子和空间效应,从而影响了该新反应。这些过程的机械学研究是放热的,为重氮膦对醛的亲核攻击提供了证据,导致甜菜碱迅速重排为重氮亚甲基正膦,在某些情况下已被检测或捕获。重氮亚甲基膦烷根据维蒂希型缩合反应与醛的第二个分子反应,并且整个过程的确定速率的步骤被认为是所得氧杂磷杂环丁烷的分解以提供羟基膦酰胺和重氮枯烯。最后,该中间体损失了分子氮,从而提供了一个瞬态卡宾,该卡宾迅速向炔烃发展。