title: Modification of (1R,2S)-1,2-diphenyl-2-aminoethanol for the highly enantioselective, asymmetric alkylation of N-diphenylphosphinoyl arylimines with dialkylzinc.
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 3c 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.
authors.affiliation: Key Laboratory for Asymmetric Synthesis and Chirotechnology of Sichuan Province, Chengdu Institute of Organic Chemistry Chinese Academy of Sciences, Chengdu, 610041, China.
authors.forename: Hai-Le
authors.initials: HL
authors.lastname: Zhang
authors.forename: Fan
authors.initials: F
authors.lastname: Jiang
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Cui
authors.forename: Liu-Zhu
authors.initials: LZ
authors.lastname: Gong
authors.forename: Ai-Qiao
authors.initials: AQ
authors.lastname: Mi
authors.forename: Yao-Zhong
authors.initials: YZ
authors.lastname: Jiang
authors.forename: Yun-Dong
authors.initials: YD
authors.lastname: Wu
mesh_terms: D000478:Alkylation; D004983:Ethanolamines / Q000138:chemical synthesis / Q000737:chemistry*; D007097:Imines / Q000138:chemical synthesis*; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
chemical_list: D004983:Ethanolamines; D007097:Imines; D008024:Ligands; D009942:Organometallic Compounds; C007514:diphenylaminoethanol; D015032:Zinc