CO_2-H_2O体系中芳香硝基化合物选择还原反应的研究

The exploration of the selective reduction of nitroarenes in CO_2-H_2O system

在CO2-H2O体系中,研究了各反应因素对锌粉选择还原芳香硝基化合物制备相应的芳香羟胺的影响.在锌粉与硝基苯的物质的量之比为3∶1,CO2压力为0.5MPa,40℃的条件下,反应3h,N-苯基羟胺的产率为76%.该法具有较高的化学选择性,带有其它可还原官能团的芳香硝基化合物也能被选择还原成相应的羟胺,苯环上带有的这些可还原的官能团不发生还原反应.苯环上带有的吸电子基团有利于此选择还原反应的进行.

Nitroarenes are selectively reduced to the corresponding N-arylhydroxylaminesusing Zn dust in CO2-H2O system, and the different factors are studied. The yield of Nphenylhydroxylamine from nitrobenzene is 76%when the reaction is carried out at 40℃for 3 hours with a Zn to nitrobenzene molar ratio equal to 3 under 0.5 MPa CO2 pressure. The method demonstrates high selectivity, other nitroarenes, which contain reducible functionality other than nitro group, are also selective reduced to the corresponding N-arylhydroxylamines, the reducible functionality other than a nitro group is not reduced. Nitroarenes bearing electron-withdrawing groups favor the reaction.