Innenrücktitelbild: Nickel‐Catalyzed Asymmetric Hydrogenation of N ‐Sulfonyl Imines (Angew. Chem. 22/2019)

Organocatalytic asymmetric transfer hydrogenation of imines

Highly enantioselective Pd-catalyzed asymmetric hydrogenation of activated imines.

Pd/bisphosphines complexes are highly effective catalysts for asymmetric hydrogenation of activated imines in trifluoroethanol. The asymmetric hydrogenation of N-diphenylphosphinyl ketimines 3 with Pd(CF3CO2)/(S)-SegPhos indicated 87-99% ee, and N-tosylimines 5 could gave 88-97% ee with Pd(CF3CO2)/(S)-SynPhos as a catalyst. Cyclic N-sulfonylimines 7 and 11 were hydrogenated to afford the useful...

Brønsted acid activation strategy in transition-metal catalyzed asymmetric hydrogenation of N-unprotected imines, enamines, and N-heteroaromatic compounds.

Asymmetric hydrogenation plays an important role in organic synthesis, but that of the challenging substrates such as N-unprotected imines, enamines, and N-heteroaromatic compounds (1H-indoles, 1H-pyrroles, pyridines, quinolines, and quinoxalines) has only received increased attention in the past three years. Considering the interaction modes of a Brønsted acid with a Lewis base, Brønsted acids...

The importance of the N-H bond in Ru/TsDPEN complexes for asymmetric transfer hydrogenation of ketones and imines.

Ru(II) complexes of TsDPEN containing two alkyl groups on the non-tosylated nitrogen atom are poor catalysts for asymmetric transfer hydrogenation of ketones and imines; this observation provides direct evidence for the importance of the N-H interaction in the transition state for ketone reduction.

Highly Enantioselective Pd-Catalyzed Asymmetric Hydrogenation of N-Diphenylphosphinyl Ketimines Enantioselective Pd-Catalyzed Asymmetric Hydrogenation of N-Diphenylphosphinyl Ketimines

Transition-metal-catalyzed asymmetric synthesis is a powerful and commonly used method for preparing a wide range of enantiomerically pure compounds.1 Among organo-transition-metal compounds, Pd complexes have become indispensable tools for both common and stateof-the art organic synthesis.2 Although a large number of Pd-based catalytic systems have been developed for many kinds of reactions, P...