Reductive properties of low-valent titanium reagents. Mechanistic studies

Abstract

The reduction of nitro compounds and the deoxygenation of N-oxides with low-valent titanium reagents were studied. The reaction conditions were optimized. Both the inorganic and the organic part of the reaction are discussed. The reaction mechanism is deduced from stoichiometric studies and EPR measurements. Formation of an intermediate complex of an organic anion-radical with titanium is proposed as the key step in the reduction of nitro compounds and the deoxygenation of N-oxides with low-valent titanium. In general, this mechanism is similar to that proposed earlier for the reductive coupling of ketones.