Highly Efficient Synthesis of N, N-Dilkylformamides from Carbon Dioxide and Dialkylamines over Ruthenium-Silica Hybrid Gels

摘要

N,N-dialkylformamides have been synthesized from CO_2, H_2 and dimethyl-or diethylamines using homogeneous bidentate ruthernium phosphine complexes as well as silica hybrid gels containing these complexes. Hybrid xero-and aerogels were prepared via a sol-gel route employing ruthenium complexes functionalized by silylether groups and tetraalkoxysilane as precursors. Xerogels possessed pronounced microporosity and exhibited much lower activity than corresponding aerogels with mesporous structure, indicating that beneficial use of the outstanding activity of the bidentate ruthenium complexes ina hybrid gel requires a suitable mesoporous structure. Bidentate ruthenium phosphine complexes as well as corresponding xero-and aerogels afforded 100 percent selectivity to the desired N,N-dialkylformamides.