SmI2-Promoted Reformatsky-Type Coupling Reactions in Exceptionally Hindered Contexts

Organic Letters 10(6), 1291-1294, DOI: 10.1021/ol800099a

Highly substituted, very hindered enones were synthesized using a two-step procedure that utilizes a diiodosamarium-promoted Reformatsky-type coupling and dehydration using Martin sulfurane. Both α-chloro- and α-bromoketones were coupled with a variety of carbonyl nucleophiles to form the intermediate β-hydroxyketones, occurring with excellent diastereoselectivity, favoring the syn isomer (R1 = Me). This technique complements other methods and enables the preparation of enones outside of the scope of current olefination methodology.