Reductive amination of various ketones and aldehydes by transferhydrogenation under aqueous conditions has been developed, by using cyclometallated iridium complexes as catalysts and formate as hydrogen source. The pH value of the solution is shown to be critical for a high catalytic chemoselectivity and activity, with the best pH value being 4.8. In comparison with that in organic solvents, the reductive
An iridiumcatalyst enables the reductive amination of carbonylgroups with unprecedented substrate scope, selectivity, and activity using formic acid as the hydrogen source (see scheme). The catalyst system provides significant improvement over commonly used boron hydrides.
The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formula: (Formula (I)) where ring B is a conjugated ring system with one or more substituents. The catalysts of the invention are particularly effective in reductive amination procedures which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
Cobalt(II) Phthalocyanine-Catalyzed Highly Chemoselective Reductive Amination of Carbonyl Compounds in a Green Solvent
作者:Vishal Kumar、Upendra Sharma、Praveen K. Verma、Neeraj Kumar、Bikram Singh
DOI:10.1002/adsc.201100645
日期:2012.3.16
Cobalt phthalocyanine has been employed for the highlychemoselectivereductiveamination of aldehydes and ketones in ethanol as a greensolvent. A large range of functional groups such as nitro, acid, amide, ester, nitrile, halogen, lactone, methoxy, hydroxy, alkene, N‐benzyl, O‐benzyl and heterocyclic rings were well tolerated under the present reaction conditions.
作者:R. Ian Storer、Diane E. Carrera、Yike Ni、David W. C. MacMillan
DOI:10.1021/ja057222n
日期:2006.1.1
The first enantioselectiveorganocatalyticreductive amination reaction has been accomplished. The development of a new chiral phosphoric acid catalyst has provided a convenient strategy for the enantioselective construction of protected primary amines and provided a highly stereoselective method for the reductive amination of heterocyclic amines. A diverse spectrum of ketone and amine substrates can