Ten Years of Research on NOBIN Chemistry

Abstract

2-Amino-2-hydroxy-1,1-binaphthyl (NOBIN, 3) can be considered as the analogue of 1,1-bi-2- naphthol (BINOL, 1) and 1,1-bi-2-naphthylamine (BINAM, 2) in terms of its functionality and scaffold. Since the first report on the synthesis of NOBIN by Kocovsky, the chemistry of NOBIN has been developed rapidly in the last decade. This article summarizes its synthesis, modification and application of its derivatives as the chiral ligands in asymmetric catalysis. The methods for the preparation of enantiopure NOBIN included asymmetric cross-coupling reaction of 2-naphthol and 2-naphthylamine, optical resolution of its racemic form and transformation from enantiopure BINOL. A variety of chiral ligands could be easily obtained by simple transformation from NOBIN. Their application in various asymmetric reactions, such as diethyl zinc addition to aldehydes, allylation of aldehydes, allylic substitutions, 1,4-addition to α,β-unsaturated ketones, aldol-type reaction, Diels-Alder and hetero-Diels-Alder reactions, transfer hydrogenation of ketones, cyclopropanation, phase-transfer catalysis of alkylations, ring-opening/cross metathesis, α-vinylation/arylation of ketones and Suzuki coupling reactions, clearly demonstrated that NOBIN has become one type of privileged scaffold for construction of various chiral ligands for asymmetric catalysis. Keywords: cross coupling, optical resolution, alkylation, asymmetric catalysis, binaphthyl, diethyl zinc addition, conjugate addition, cyclopropanation, transfer hydrogenation, aldol reaction