Chiral Bifunctional N-Heterocyclic Carbenes: Synthesis and Application in the Aza-Morita-Baylis-Hillman Reaction
作者:Song Ye、Lin He、Yan-Rong Zhang、Xue-Liang Huang
DOI:10.1055/s-2008-1067216
日期:2008.9
A series of chiral bifunctional N-heterocyclic carbene (NHC) precursors with a proximal hydroxy group were smoothly prepared from l-pyroglutamic acid. Promising enantiomeric excesses (up to 44% ee) were achieved for the bifunctional NHC-catalyzed enantioselective aza-Morita-Baylis-Hillman reaction of cyclopent-2-enone with N-tosylphenylmethanimine.
Enantioselective [4+2] cycloaddition of ketenes and 9,10-phenanthrenequinone catalyzed by N-heterocyclic carbenes
作者:Pan-Lin Shao、Xiang-Yu Chen、Li-Hui Sun、Song Ye
DOI:10.1016/j.tetlet.2010.02.122
日期:2010.4
Chiral N-heterocycliccarbenes were found to be efficient catalysts for the formal [4+2] cycloaddition reaction of alkyl(aryl)ketenes and 9,10-phenanthrenequinone to give the corresponding cycloadducts in good yields with high enantioselectivities.