Studies on the Mechanism, Selectivity, and Synthetic Utility of Lactone Reduction Using SmI<sub>2</sub> and H<sub>2</sub>O
作者:Dixit Parmar、Lorna A. Duffy、Dhandapani V. Sadasivam、Hiroshi Matsubara、Paul A. Bradley、Robert A. Flowers、David J. Procter
DOI:10.1021/ja906396u
日期:2009.10.28
esters and lactones have long been thought to lie outside the reducing range of SmI(2), activation of the lanthanide reagent by H(2)O allows some of these substrates to be manipulated in an unprecedented fashion. For example, the SmI(2)-H(2)O reducing system shows complete selectivity for the reduction of 6-membered lactones over other classes of lactones and esters. The kinetics of reduction has been
尽管长期以来一直认为简单的脂肪族酯和内酯位于 SmI(2) 的降低范围之外,但 H(2)O 对镧系元素试剂的激活允许以前所未有的方式操纵其中的一些底物。例如,SmI(2)-H(2)O 还原系统显示出相对于其他类别的内酯和酯还原 6 元内酯的完全选择性。使用停流分光光度法研究了还原动力学。实验和计算研究表明选择性的起源在于初始电子转移到内酯羰基。在用 SmI(2)-H(2)O 进行内酯还原过程中形成的自由基中间体可用于环化,以提供具有高非对映选择性的环状酮(或缩酮)产品。