Regio- and stereoselective multisubstituted olefin synthesis via hydro/carboalumination of alkynes and subsequent iron-catalysed cross-coupling reaction with alkyl halides

Abstract

A new synthetic route towards multisubstituted olefins, which are recurring core units in various pharmaceutical and bioactive compounds, was developed based on the direct cross coupling of alkenylaluminium reagents which were prepared in situ by the hydro- and carbometalation of alkynes, with non-activated alkyl halides in the presence of an iron catalyst. For the first time, alkenylaluminium reagents participated in an iron-catalysed cross-coupling reaction, following the activation of the aluminium reagents by a metal fluoride. The hydro- and carboalumination of alkynes and the subsequent cross-coupling reactions could be conducted in a one-pot manner and proceeded regio- and stereoselectively to give a variety of di-, tri-, and tetrasubstituted alkenes in good to excellent yields.