Origin of 1, 3-induction in the addition of alkyl lithium to imines bearing an N-stereogenic center
作者:Nancy、Soma Ghosh、Nishan Singh、Gurmeet Kaur Nanda、P. Venugopalan、Prasad V. Bharatam、Sanjay Trehan
DOI:10.1039/b300478c
日期:——
The origin of diastereoselectivity in the addition of alkyl lithium to chiral Schiff bases has been investigated experimentally and theoretically and the formation of the major diastereomer can be explained from the energy minimized structure of the Schiff base in which the phenyl group has been found to orient in such a manner that it posed lesser steric hindrance to the incoming nucleophile as compared to the alkyl group
Copper-Catalyzed Asymmetric Conjugate Addition with Chiral SimplePhos Ligands
作者:Laëtitia Palais、Alexandre Alexakis
DOI:10.1002/chem.200901577
日期:2009.10.12
they can be highly functionalised. Herein we report the copper‐catalysed asymmetricconjugateaddition of diethyl zinc and trialkylaluminium reagents with SimplePhos ligands, which gives high enantioselectivity with cyclic enones, acyclic enones and nitro‐olefins, with up to 98.6 % ee. Of particular interest is the reaction of trialkylaluminium reagents with a wide range of 3‐substituted enones, thus
Metal-free diastereoselective catalytic hydrogenations of imines using B(C6F5)3
作者:Zachariah M. Heiden、Douglas W. Stephan
DOI:10.1039/c1cc10438a
日期:——
Reductions of chiral ketimines effected under H(2) by catalytic amounts of B(C(6)F(5))(3) result in moderate to excellent diastereoselectivities. In the case of camphor and menthone derived imines, the reductions proceeded with greater than 95% diastereoselectivity.