Enantioselective organocatalytic Michael-hemiketalization catalyzed by a trans-bifunctional indane thiourea catalyst
作者:Yaojun Gao、Qiao Ren、Swee-Meng Ang、Jian Wang
DOI:10.1039/c1ob05404j
日期:——
An efficient, convenient and enantioselective Michael-hemiketalization reaction has been developed for the synthesis of naphthoquinones. In this work, a novel trans-bifunctional indane thiourea catalyst has been reported to promote this process to afford high yields (up to 99%) and high to excellent enantiomeric excesses (90–98% ee).
Enantioselective Synthesis of Coumarins Catalyzed by a Bifunctional Amine-Thiourea Catalyst
作者:Yaojun Gao、Qiao Ren、Lei Wang、Jian Wang
DOI:10.1002/chem.201002202
日期:2010.11.22
Efficient excess: An efficient and facile enantioselective Michael addition reaction through hydrogen‐bonding catalysis for the synthesis of coumarin complexes has been developed (see scheme). A simple bifunctional amine–thiourea small molecule has been discovered to catalyze this process with high yields and high to excellent enantiomeric excesses.
An efficient asymmetriccascadereaction catalyzed by a chiral bifunctional indane amine–thiourea catalyst has been developed. From a broad substrate scope, chiral dihydro-2H-pyran complexes that contained two stereogenic centers were obtained in a one-pot manner in good to excellent yields (72–97%) and high to excellent stereoselectivities (92–97% ee).
Asymmetric organocatalytic cascade Michael/hemiketalization/retro-Henry reaction of β,γ-unsaturated ketoesters with α-nitroketones
作者:Yaojun Gao、Qiao Ren、Woon-Yew Siau、Jian Wang
DOI:10.1039/c1cc11124h
日期:——
An unprecedented enantioselective organocatalytic Michael/hemiketalization/retro-Henry cascade sequence is described, which catalyzed by a simple bifunctional indane amine-thiourea catalyst. This process provides a new route to the enantioselective synthesis of 5-nitro-pent-2-enoates, a precursor to α-ketolactam.