The Effect of Alkyl Substituents on the Formation and Structure of Homochiral (*,*)-[RGa(-OCH(Me)COR')] Species-Towards the Factors Controlling the Stereoselectivity of Dialkylgallium Alkoxides in the Ring-Opening Polymerization of -Lactide.

Building on our previous studies, which have demonstrated that homochiral propagating species-(,)-[MeGa(-OCH(Me)COR)]-were crucial for the heteroselectivity of [MeGa(-OCH(Me)COMe)] in the ring-opening polymerization (ROP) of racemic lactide (-LA), we have investigated the effect of alkyl groups on the structure and catalytic properties of dialkylgallium alkoxides in the ROP of -LA. Therefore, we have isolated and characterized the -[RGa(-OCH(Me)COMe] (R = Et (), Pr () and -[RGa(-OCH(Me)CHN] (R = Et (), Pr ()) complexes, to demonstrate the effect of alkyl groups on the chiral recognition induced the formation of the respective homochiaral species-(,)-[RGa(-OCH(Me)COMe)] and (,)-[RGa(-OCH(Me)CHN]. Moreover, we have investigated the structure of (,)-[RGa(-OCH(Me)COMe] (R = Et ((,)-, R = Pr ((,)-,) and their catalytic activity in the ROP of -LA. With an increase in the bulkiness of alkyl substituents on gallium the following can be observed: (a) the tendency for the formation of homochiral complexes decreased, (b) the symmetry of homochiral (,)-[RGa(-OCH(Me)COMe] (M = Me, Et (,)-), Pr (,)-) changed, and both have resulted in (c) lower or no heteroselectivtity across these complexes in the ROP of -LA. Importantly, the results have confirmed the crucial role of the chiral-induced formation of homochiral asymmetric dimers on the heteroselectivity of dialkylgallium alkoxides in the ROP of -LA.