Catalytic enantioselective 1,3-dipolar cycloadditions of alkyl diazoacetates with alpha,beta-disubstituted acroleins.
A catalytic route to highly functionalized chiral 2-pyrazolines by an asymmetric 1,3-dipolar cycloaddition reaction of ethyl diazoacetate with alpha-substituted and alpha,beta-disubstituted acroleins has been developed; in the presence of chiral (S)-oxazaborolidinium ion as catalyst, the reaction proceeded with high to excellent enantioselectivities (up to 99% ee).
Gao
Lizhu
L
Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea.
Hwang
Geum-Sook
GS
Lee
Mi Young
MY
Ryu
Do Hyun
DH