Progress in the trans-reduction and trans-hydrometalation of internal alkynes. Applications to natural product synthesis

Abstract

The classical repertoire of synthetic organic chemistry is short of methods that allow triple bonds to be transformed into (E)-alkenes with high selectivity in the presence of other reducible sites. Recent advances, most notably in rutheniumcatalyzed trans-hydrogenation, trans-hydrosilylation, transhydrogermylation, trans-hydrostannation, and even transhydroboration hold the promise of filling this gap. This review illustrates the state-of-the-art in the field by summarizing applications of these emerging methodologies to natural product synthesis. A comparison of ruthenium-catalyzed and radicalinduced trans-hydrostannations provides further insights into the application profile of these transformations.