Lithium Diisopropylamide Solvated by Hexamethylphosphoramide: Substrate-Dependent Mechanisms for Dehydrobrominations
作者:Yun Ma、Antonio Ramirez、Kanwal Jit Singh、Ivan Keresztes、David B. Collum
DOI:10.1021/ja060964b
日期:2006.12.1
Lithiumdiisopropylamide-mediated dehydrobrominations of exo-2-bromonorbornane, 1-bromocyclooctene, and cis-4-bromo-tert-butylcyclohexane were studied in THF solutions and THF solutions with added hexamethylphosphoramide (HMPA). Rate studies reveal a diverse array of mechanisms based on mono-, di-, and trisolvated monomers as well as triple ions. The results are contrasted with analogous eliminations