Highly chemoselective hydrogenation of cyclic imides to ω-hydroxylactams or ω-hydroxyamides catalyzed by iridium catalysts†
Abstract
Several novel ferrocene-based PNN ligands were prepared, which were found to be highly effective catalysts (TON up to 50 000) for the homogeneous hydrogenation of cyclic imides with iridium. The hydrogenation mode (type I: ring opening/type II: non-ring opening) could be finely tuned by tiny changes in the ligands. Using this straightforward strategy, a plethora of ω-hydroxylactams and ω-hydroxyamides with different functional groups were obtained in high yield.