A Cu-catalysed method for the preparation of highly substituted methylenecyclopentanes, through a sequence involving a Michael addition of stabilized enolates to activated enynes followed by an intramolecular carbocupration reaction, is presented. This method was also successfully combined

Access to nonracemic amino ketones via a hydrozirconation/transmetalation/acylation sequence applied to Boc-protected 1-aminobut-3-enes is presented. This method was applied to the stereoselective synthesis of cyclic imines (or iminiums) which were diastereoselectively converted into 2-cis-substituted and 2,6-cis-disubstituted piperidines. The potential of this approach in the field of alkaloid synthesis was illustrated by the synthesis of (-)-coniine and (-)-indolizidine 209D. Furthermore, access to indolizidines bearing a quaternary center could also be envisioned through this strategy.

We report herein the synthesis and applications of 1-(trifluoromethyl)cyclopent-3-ene-1-carboxylic acid and its esters, promising new trifluoromethylated cyclic building blocks. Initially prepared starting from a pentafluorodithiopropanoic ester, a more convenient and effective approach