Catalytic Enantioselective Addition of Dialkylzinc to <i>N</i>-Diphenylphosphinoylimines. A Practical Synthesis of α-Chiral Amines
作者:Alessandro A. Boezio、André B. Charette
DOI:10.1021/ja027673x
日期:2003.2.19
The enantioselectiveaddition of dialkylzincreagents to N-diphenylphosphinoylimines derived from aryl-, furyl-, and cyclopropylaldehydes is efficiently catalyzed by a copper(II) triflate/(R,R)-MeDUPHOS complex. The yields are high (51-98%), and the enantiomeric excesses vary from 85 to 96%. This route provides a practical route to alpha-chiral amines.
Modification of (1R,2S)-1,2-Diphenyl-2-aminoethanol for the Highly Enantioselective, Asymmetric Alkylation ofN-Diphenylphosphinoyl Arylimines with Dialkylzinc
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
Enantioselective Addition of Dialkylzinc to Aromatic Aldimines Mediated by Camphor-Derived Chiral β-Amino Alcohols
作者:Wei-Ming Huang、Biing-Jiun Uang
DOI:10.1002/asia.201403240
日期:2015.4
The enantioselective addition of diethylzinc or dimethylzinc to N‐(diphenylphosphinoyl)imines mediated by 1 or 2 could be achieved in high yields (70–97 %) and enantioselectivities (85–98 % ee). The catalytic loading of 1 or 2 a could be reduced to 10 mol % for methylation or ethylation of imines in high yields and enantioselectivities (79–96 %) when the reaction was conducted in the presence of 1
The present invention relates to a method of enantioselective addition to imines, including: reacting R
2
CH═NY with R
3
ZnR
4
in the presence of a compound represented by the following formula (I),
in which Y, R
1
, R
2
, R
3
and R
4
are defined the same as the specification. Accordingly, the present invention can prepare secondary amines in high yields and enantiomeric excess by the above-mentioned method.
Asymmetric Addition of Diethylzinc to Diphenylphosphinoyl-Imines Catalyzed by Copper(II) Trifluoromethanesulfonate-Chiral (2′-Ethylamino-[1,1′]binaphthalenyl-2-yl)-thiophosphoramidic AcidO,O′-Diaryl Ester Ligands
作者:Min Shi、Zhi-Yu Lei、Qin Xu
DOI:10.1002/adsc.200606128
日期:2006.10
The chiral binaphthylthiophosphoramide L1 prepared from the reaction of O,O-diphenyl chlorothiophosphate with (R)-(+)-N-ethyl-1,1′-binaphthyl-2,2′-diamine was used as a catalytic chiral ligand in the copper(II) trifluoromethanesulfonate-promoted asymmetricaddition of diethylzinc to diphenylphosphinoyl-imines to give the corresponding adducts in 90–98 % ee and good yields under mild conditions.