Non-Carbonyl-Stabilized Metallocarbenoids in Synthesis: The Development of a Tandem Rhodium-Catalyzed Bamford−Stevens/Thermal Aliphatic Claisen Rearrangement Sequence
作者:Jeremy A. May、Brian M. Stoltz
DOI:10.1021/ja028020j
日期:2002.10.1
Bamford-Stevens/Claisen rearrangement is presented. The tandem reaction uses Eschenmoser hydrazones for the in situ generation of non-carbonyl-stabilized diazo alkanes, which are presumably intercepted by Rh(II) catalysts to induce a 1,2-hydride migration. This sequence provides high levels of stereocontrol for the generation of simple acyclic (Z)-enol ethers. These enol ethers undergo either thermal or Lewis
提出了串联铑催化的 Bamford-Stevens/Claisen 重排。串联反应使用 Eschenmoser 腙原位生成非羰基稳定的重氮烷烃,可能被 Rh(II) 催化剂拦截以诱导 1,2-氢化物迁移。该序列为生成简单的无环 (Z)-烯醇醚提供了高水平的立体控制。这些烯醇醚经历热或路易斯酸加速的克莱森重排以提供高非对映纯度的产物。还介绍了级联反应,其中第三个化学步骤发生在初始串联序列之后(即 Bamford-Stevens/Claisen/ene 和 Bamford-Stevens/Claisen/Cope)。