Enantioselective Cyclopropanation of Allylic Alcohols. The Effect of Zinc Iodide
作者:Scott E. Denmark、Stephen P. O'Connor
DOI:10.1021/jo9702397
日期:1997.5.1
catalytic, enantioselective cyclopropanation of allylic alcohols is examined with bis(iodomethyl)zinc as the reagent and bis-methanesulfonamide 7 as the catalyst. Significant rate enhancement was observed when 1 equiv of zinc iodide was present, but more importantly, the enantiomeric excess of the product cyclopropane increased from 80% to 89% for the substrate cinnamyl alcohol. Reaction studies and spectroscopic
以双(碘甲基)锌为试剂,以双甲磺酰胺7为催化剂,研究了碘化锌对烯丙基醇催化,对映选择性环丙烷化的影响。当存在1当量的碘化锌时,观察到速率显着提高,但是更重要的是,底物肉桂醇的产物环丙烷的对映体过量从80%增加到89%。反应研究和光谱研究表明,这种显着影响是通过Schlenk平衡进行试剂修饰的结果,该平衡产生了更具反应性和选择性的碘化锌(碘甲基)。