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.
Highly Diastereo- and Enantioselective Synthesis of α-Alkyl Norstatine Derivatives: Catalytic Asymmetric Mannich Reactions of 5H-Oxazol-4-ones
作者:Depeng Zhao、Linqing Wang、Dongxu Yang、Yixin Zhang、Rui Wang
DOI:10.1002/anie.201201804
日期:2012.7.23
Going Mannich: The title reaction results in the first catalyticasymmetricsynthesis of syn‐α‐alkyl norstatine derivatives. Excellent enantioselectivities and diastereoselectivities were achieved with a series of N‐diphenylphosphinoyl‐protected imines and 5H‐oxazol‐4‐ones by using the catalyst 1/Zn. Importantly, the involvement of the diethyl phosphoramidate 2 was critical to achieve good enantioselectivities