Bis-sulfonyl ethylene as masked acetylene equivalent in catalytic asymmetric [3 + 2] cycloaddition of azomethine ylides.
Enantioenriched 3-pyrrolines have been synthesized by highly enantioselective Fesulphos-Cu-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with trans-1,2-bisphenylsulfonyl ethylene, followed by reductive sulfonyl elimination. High levels of reactivity, exoselectivity, and enantioselectivity have been accomplished for a variety of substituted azomethine ylides. This cycloaddition-desulfonylation strategy has been applied as a key step in the enantioselective synthesis of a biologically active C-azanucleoside.
López-Pérez
Ana
A
Departamento de Química Orgánica, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco 28049 Madrid, Spain.
Adrio
Javier
J
Carretero
Juan C
JC