Highly enantioselective reduction of ketones in air catalyzed by Rh-based macrocycles

Cinchona-Alkaloid-Derived NNP Ligand for Iridium-Catalyzed Asymmetric Hydrogenation of Ketones

“…Encouraged by this fundamental study, numerous ligands including bidentate, tridentate, and even multidentate ligands were successfully developed for the asymmetric hydrogenation of prochiral ketones, such as BICP, 4 MiniPhos, 5 binapine, 6 ferrocene-based ligands, 7 Xylbinap, 8 TolBINAP, 9 TunePhos, 10 PhanePhos, 11 spiro diphosphines, 12 hemisalen type ligands, 13 PNN, 14 PNNP, 15 heterocyclic ligands, 16 N-tosylethylenediamine, 17 and macrocyclic ligands. 18 Most of these ligands were synthesized to mimic the Noyori catalyst via multistep complicated reactions with expensive chemical reagents, which limited their application. Therefore, it is still a challenge to develop more effective and practical ligands in terms of enantioselectivity and reactivity, tolerance to a variety of functional groups, and ease of preparation in asymmetric catalysis.…”

“…These catalysts have been applied to the asymmetric synthesis of various important pharmaceuticals including ( R )-denopamine, ( R )-fluoxetine, BMS 181100, and ( S )-duloxetine. Encouraged by this fundamental study, numerous ligands including bidentate, tridentate, and even multidentate ligands were successfully developed for the asymmetric hydrogenation of prochiral ketones, such as BICP, MiniPhos, binapine, ferrocene-based ligands, Xylbinap, TolBINAP, TunePhos, PhanePhos, spiro diphosphines, hemisalen type ligands, PNN, PNNP, heterocyclic ligands, N -tosylethylenediamine, and macrocyclic ligands . Most of these ligands were synthesized to mimic the Noyori catalyst via multistep complicated reactions with expensive chemical reagents, which limited their application.…”