Mechanistic Implications in the Morita−Baylis−Hillman Alkylation: Isolation and Characterization of an Intermediate
作者:Marie E. Krafft、Thomas F. N. Haxell、Kimberly A. Seibert、Khalil A. Abboud
DOI:10.1021/ja057595o
日期:2006.4.5
An intermediate phosphonium salt has never been isolated from the Morita-Baylis-Hillman (MBH) reaction. Due to the weakly basic counterion produced in the MBH alkylation and allylation reactions, the reaction can be stopped after electrophilic attack on the zwitterionic enolate and an intermediate isolated. Upon analysis of the crystal structure, a trans geometry is observed, suggesting that there is no electrostatic interaction between phosphorus and oxygen in the zwitterionic enolate that undergoes alkylation, thus giving new mechanistic insight into the MBH reaction.
Unprecedented reactivity in the Morita–Baylis–Hillman reaction; intramolecular α-alkylation of enones using saturated alkyl halides
作者:Marie E. Krafft、Kimberly A. Seibert、Thomas F. N. Haxell、Chitaru Hirosawa
DOI:10.1039/b512665g
日期:——
sp3 Hybridized electrophiles, never before used in the organomediated MoritaâBaylisâHillman reaction, now facilitate the formation of five- and six-membered enone cycloalkylation products.