Catalytic carbonylation of nitro compounds with carbon monoxide in presence of rhodium-carbonyl hydride complex

Abstract

1. The rhodium carbonyl hydride complex RhH(CO) (PPh3)3 is an active catalyst for the synthesis of phenyl isocyanate, the o-, m-, and p-tolyl isocyanates, and mesityl isocyanate from the corresponding aromatic nitro compounds by carbonylation with CO. The optimum reaction conditions were determined (pressure, temperature, time, substrate/catalyst ratio). 2. The use of MoCl5 as a cocatalyst increases the conversion of the nitro compound, the yield of the isocyanate, and the selectivity of the process. 3. Methyl substituents in the o-position activate the nitro group when nitro compounds are carbonylated with CO.