Enantioselective aza-Henry reaction using cinchona organocatalysts
作者:Luca Bernardi、Francesco Fini、Raquel P. Herrera、Alfredo Ricci、Valentina Sgarzani
DOI:10.1016/j.tet.2005.09.076
日期:2006.1
The aza-Henryreaction of imines with nitromethane was promoted by cinchona alkaloids and modified cinchona bases to give optically active β-nitroamines. Various N-protected imines were examined as substrates. N-Boc, N-Cbz, and N-Fmoc protected imines gave the best results in terms of chemical yields and enantioselectivities. After a careful screening of a series of chiral bases, very good enantioselectivities