Aluminum, Indium, and Mixed Yttrium–Lithium Complexes Supported by a Chiral Binap-Based Fluorinated Dialkoxide: Structural Features and Heteroselective ROP of Lactide

Nicolas Maudoux , Thierry Roisnel (1) , Jean-François Carpentier (1) , Yann Sarazin (1)

1 ISCR - Institut des Sciences Chimiques de Rennes

The new chiral Binap-based fluorinated dialcohol proteo-ligand {ONNO}H2 has been prepared under its enantiomerically pure and racemic forms following reaction of (R)- or (rac)-1,1′-binaphthyl-2,2′-diamine with 5,5,5-trifluoro-4-hydroxy-4-(trifluoromethyl)pentan-2-one. The racemic proteo-ligand reacts with the trivalent metallic precursors AlEt2Cl and In(CH2SiMe3)3 to yield the complexes (rac)-{ONNO}AlCl (1) and (rac)-{ONNO}In(CH2SiMe3) (2), while the reaction of (R)-{ONNO}H2 with a 1:1 mixture of Y(N(SiMe3)2)3 and LiN(SiMe3)2 gives the enantiomerically pure heterobimetallic [((R)-{ONNO})2Y·Li] (3). Complex 3 acts as a single-component initiator for the near-perfect heteroselective ring-opening polymerization (ROP) of racemic lactide, yielding polymers with Pr up to 0.99 under mild conditions. It also produces syndiotactic-enriched polylactide (Pr = 0.80) by ROP of meso lactide.

Domains: Chemical Sciences

Nicolas Maudoux, Thierry Roisnel, Jean-François Carpentier, Yann Sarazin. Aluminum, Indium, and Mixed Yttrium–Lithium Complexes Supported by a Chiral Binap-Based Fluorinated Dialkoxide: Structural Features and Heteroselective ROP of Lactide. Organometallics, 2014, 33 (20), pp.5740-5748. ⟨10.1021/om500458g⟩. ⟨hal-01114338⟩