Lithium butylchalcogenolate induced Michael-aldol tandem sequence: easy and rapid access to highly functionalized organochalcogenides and unsaturated compounds

Lithium ""butylchalcogenolates are generated in situ by reacting the elements (S, Se, and Te) with (n)butyl-lithium at 0 degrees C. Reaction of the lithium alkylchalcogenolates with activated alkenes and aldehydes gives the corresponding aldol adducts. The selenium-containing products give Morita-Baylis-Hillman adducts after the oxidation/elimination of the selenoxide. The whole sequence can be performed in a one-pot procedure. (C) 2009 Elsevier Ltd. All rights reserved.