Neutral Yttrium Tris(amide) and Ate Complexes Coordinated by an (R)‐N,N′‐Diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamido Ligand as Enantioselective Catalysts for Intramolecular Hydroamination

Abstract

AbstractA bis(amido)yttrium chloride coordinated by (R)‐N,N′‐diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamide [Y{(R)‐C20H12(NiPr)2}Cl(thf)2] has been prepared and characterized by X‐ray analysis along with the corresponding yttrium ate complex [Li(thf)4][Y{(R)‐C20H12(NiPr)2}2]. The reaction of [(R)‐N,N′‐diisopropyl‐1,1′‐binaphthyl‐2,2′‐diamido]yttrium chloride with lithium diisopropylamine leads to the formation of a neutral tris(amido)yttrium complex which was characterized by NMR spectroscopy. The new complexes [Y{(R)‐C20H12(NiPr)2}{NiPr2}] and [{Li(thf)4}(Y{(R)‐C20H12(NiPr)2}2)], which contain the same enantiopure binaphthyldiamido ligand, are compared for the catalysis of several intramolecular hydroamination reactions. Both complexes provide pyrrolidines andpiperidines with moderate to high enantioselectivities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)