title: N-heterocyclic carbene catalyzed carba-, sulfa-, and phospha-Michael additions with NHC·CO₂ adducts as precatalysts.
abstract: N-heterocyclic carbene catalyzed Michael additions have been revisited with 1,3-dialkyl- or 1,3-diarylimidazol(in)ium-2-carboxylates, that is, NHC·CO2 adducts, as the source of the free NHC catalysts in solution. Using these precatalysts, a number of efficient carba-, sulfa-, and phospha-Michael additions were achieved very conveniently, without the need for an external strong base to generate the NHC by deprotonation of an azolium salt. To further expand the scope of the procedure, some NHC-catalyzed sulfa-Michael/aldol organocascades were also investigated.
authors.affiliation: Laboratory of Organometallic Chemistry and Homogeneous Catalysis, Institut de chimie (B6a), Université de Liège , Sart-Tilman par 4000 Liège, Belgium.
authors.forename: Morgan
authors.initials: M
authors.lastname: Hans
authors.forename: Lionel
authors.initials: L
authors.lastname: Delaude
authors.forename: Jean
authors.initials: J
authors.lastname: Rodriguez
authors.forename: Yoann
authors.initials: Y
authors.lastname: Coquerel