and (c) release of the initially formed iminol, which rapidly tautomerises to the
amide product in solution, to regenerate the catalyst. Studies of catalyst speciation
suggest that during turnover, the active catalyst 9 is in equilibrium with the aqua
complex III and the carboxamide complex IV; thus, the product amide and water are
competitive inhibitors. Nevertheless, the ligand exchange processes are rather fast
enabling efficient catalysis, in spite of these inhibitors.
Scheme 51 MLC hydration of nitriles catalysed by 9
368
B. Guo et al.
amide product in solution, to regenerate the catalyst. Studies of catalyst speciation
suggest that during turnover, the active catalyst 9 is in equilibrium with the aqua
complex III and the carboxamide complex IV; thus, the product amide and water are
competitive inhibitors. Nevertheless, the ligand exchange processes are rather fast
enabling efficient catalysis, in spite of these inhibitors.
Scheme 51 MLC hydration of nitriles catalysed by 9
368
B. Guo et al.