Enantioselective addition of aryl ketones and acetone to nitroalkenes organocatalyzed by carbamate-monoprotected cyclohexa-1,2-diamines
摘要:
Enantiomerically pure carbamate-monoprotected trans-cyclohexane-1,2-diamines are used as chiral organocatalysts for the addition of aryl ketones and acetone to nitroalkenes to give enantioenriched beta-substituted gamma-nitroketones. The reaction was performed in the presence of 3,4-dimethoxybenzoic acid as an additive, in chloroform as the solvent at room temperature, achieving enantioselectivities up to 96%. Theoretical calculations are used to justify the observed sense of the stereoinduction. (C) 2015 Elsevier Ltd. All rights reserved.
Synthesis of multisubstituted 1H-pyrrole: selenium-catalyzed reaction of γ-nitro substituted carbonyl compounds and carbon monoxide
作者:Rui Umeda、Tsukasa Mashino、Yutaka Nishiyama
DOI:10.1016/j.tet.2014.04.061
日期:2014.7
The novel and efficient selenium-catalyzed reductiveN-heterocyclization of γ-nitro substituted carbonyl compounds with carbon monoxide has been developed. Various multisubstituted 1H-pyrroles can be easily prepared by this protocol. The one-pot synthesis of ethyl 1H-pyrrole-3-carboxylate derivatives was also successfully attained by the selenium-catalyzed reaction of β-ketoester, vinyl nitro compounds and