| abstract |
Urethane compounds are prepared by reaction of organic nitrogen compounds with carbon monoxide in the presence of organic compound(s) containing hydroxyl (OH) group(s), using a catalyst system (A) and/or (B). (A)comprises (a) a sub-group VIII metal compound, (b) a bisphosphane of formula (I) and (c) protonic and/or Lewis acid(s). (B) comprises a compound of formula (II). R1-R4 = aliphatic, cycloaliphatic, alkylaryl or arylalkyl, (all with C atoms optionally replaced by hetero-atoms; and PR1R2 and/or PR3R4 may form a ring; M = a sub-group VIII metal; L1, L2 = weakly co-ordinating ligands, organic acid group ligands, alkyl, aralkyl, allyl substituents or halide ligands; X = a weakly co-ordinating anion; n = 0-2. Also claimed is a method of preparing isocyanates by thermal splitting of the urethanes obtained. |