Chiral NHC-catalyzed 1,3-dipolar [3 + 2] cycloaddition of azomethine imines with α-chloroaldehydes for the synthesis of bicyclic pyrazolidinones
作者:Limin Yang、Yunbo Lv、Fei Wang、Guofu Zhong
DOI:10.1039/c8ob00925b
日期:——
A chiral N-heterocyclic carbene (NHC)-catalyzed 1,3-dipolar [3 + 2] cycloaddition reaction of 3-oxopyrazolidin-1-ium-2-ides and α-chloroaldehydes was developed for the synthesis of pyrazolo[1,2-a]pyrazole-1,7-diones in moderate to good yields (up to 76%) with good enantioselectivities (up to 98% ee) and diastereoselectivities (up to 8 : 1 dr).
<i>N</i>-Heterocyclic Carbene (NHC)-Catalyzed Highly Diastereo- and Enantioselective Oxo-Diels–Alder Reactions for Synthesis of Fused Pyrano[2,3-<i>b</i>]indoles
作者:Limin Yang、Fei Wang、Pei Juan Chua、Yunbo Lv、Liang-Jun Zhong、Guofu Zhong
DOI:10.1021/ol301175z
日期:2012.6.1
A chiral N-heterocyclic carbene (NHC)-catalyzed Diels-Alder reaction of 2-oxoindolin-3-ylidenes and alpha-chloroaldehydes was developed for the synthesis of fused pyrano[2,3-b]indoles in good to excellent yields (up to 99%) with high cis-diastereoselectivities (>99:1 dr) and enantioselectivities (up to >99% ee).