An economic, practical access to enantiopure 1,1′-bi-2-naphthols: enantioselective complexation of threo-(1S,2S)-N-benzyl-N,N-dimethyl[1,3-dihydroxy-1-(4′-nitrophenyl)]-2-propylammonium chloride

An Overview of Highly Optically Pure Chloramphenicol Bases: Applications and Modifications

“…It has been reported that this enantiomerically pure acid can be easily prepared using the N,N-dimethyl derivative of (1R,2R)-ANP (4) as a resolution agent [23]. Threo-(1S,2S)-N-benzyl-N,N-dimethyl-[1,3-dihydroxyl-1-(4'-nitrophenyl)]-2-propylammonium chloride (BDDNPAC) (5) [24] and the condensation product (CHANP) (6) of (1S,2S)-ANP and cyclohexanone [25] were prepared using (1S,2S)-ANP as a chiral starting material. These two chiral regents have been successfully applied to the resolution of racemic 1,1′-bi-2-naphthols (BINOLs).…”

Update 1 of: BINOL: A Versatile Chiral Reagent

“…Simple and convenient methods of resolution of rac -BINOL 1 have been widely developed through selective crystallization of diastereomeric complexes obtained using various chiral auxiliaries. Thus, chiral m -tolyl methyl sulfoxide 28 , , chiral tartaric acid derivative 29 , , (1 R ,2 R )-diaminocyclohexane 30 , − ( S )-proline derivatives 31a − 31b , − and, more recently, chiral N -benzylcinchonidinium chloride 32 , − ( R )-α-methylbenzylamine 11 , , and threo -(1 S ,2 S )- N -benzyl- N , N -dimethyl-[1,3-difydrocyl-1-(4‘-nitrophenyl)]-2-propyammonium chloride 33 proved to be efficient (Scheme ).…”

“…Simple and convenient methods of resolution of rac-BINOL 1 have been widely developed through selective crystallization of diastereomeric complexes obtained using various chiral auxiliaries. Thus, chiral m-tolyl methyl sulfoxide 28, 82,83 chiral tartaric acid derivative 29, 84,85 (1R,2R)diaminocyclohexane 30, [86][87][88] (S)-proline derivatives 31a-31b, [89][90][91][92] and, more recently, chiral N-benzylcinchonidinium chloride 32, [93][94][95][96][97][98][99] (R)-R-methylbenzylamine 11, 73,100 and 101 proved to be efficient (Scheme 15). In all cases, the resolution was achieved in moderate to very good chemical yields (38-99%) and in enantiomeric excesses varying from 66 to 99% ee depending on the nature of the chiral auxiliary used (Table 2).…”