1,2-Migration in Rhodium(II) Carbene Transfer Reaction: Remarkable Steric Effect on Migratory Aptitude
作者:Fengping Xiao、Jianbo Wang
DOI:10.1021/jo0605391
日期:2006.7.1
been prepared in order to investigate the stericeffect in 1,2-migration reaction of rhodium(II) carbene. Through the investigation on the diazo decomposition of these compounds with Rh2(OAc)4, it was found that the stericeffect could dramatically influence the migratory aptitude. In many cases, the stericeffect could override the inherent electronic effect of the substituent.
route to β-enamino esters 1, using accessible starting materials, was developed. Lithiated enamines are allowed to react with diethyl carbonate or benzyl chloroformate with the formation of the β-enamino esters 1a or 1b. The reaction is rather general from a wide array of ketimines and aldimines. Products included cyclic β-enamino esters 1aa-ac, very useful for the synthesis of natural products.