The first facile stereoselectivity switch in the polymerization of rac-lactide-from heteroselective to isoselective dialkylgallium alkoxides with the help of N-heterocyclic carbenes

The reaction of N-heterocyclic carbene (NHC) with dimeric dialkylgallium alkoxides, acting as nonselective or heteroselective catalysts in the polymerization of rac-LA, leads to highly active and isoselective monomeric Me2Ga(NHC)OR catalysts, resulting for the first time in the facile switch of stereoselectivity.