Showing papers by "Liu-Zhu Gong published in 2004"
TL;DR: Experimental studies on the modification of (1R,2S)-1,2-diphenyl-2-aminoethanol revealed that N-monosubstituted amino alcohols exhibited higher enantioselectivities than their N,N-disubst ituted counterparts and imino alcohols.
Abstract: Experimental studies on the modification of (1R,2S)-1,2-diphenyl-2-aminoethanol, which is used to promote the alkylation of N-diphenylphosphinoyl benzalimine with diethylzinc, revealed that N-monosubstituted amino alcohols exhibited higher enantioselectivities than their N,N-disubstituted counterparts and imino alcohols. Application of the optimal chiral ligand 3 c to activate the reaction of N-diphenylphosphinoyl arylimines with diethylzinc and dibutylzinc resulted in excellent enantiomeric selectivities of up to 98 % ee. The origin of the experimentally observed enantioselectivities was revealed by density functional calculations (B3LYP/6-31G*) on the transition structures of several model reactions.
31 citations