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
Highly Enantioselective Reductive Amination of Simple Aryl Ketones Catalyzed by Ir−f-Binaphane in the Presence of Titanium(IV) Isopropoxide and Iodine
作者:Yongxiang Chi、Yong-Gui Zhou、Xumu Zhang
DOI:10.1021/jo026856z
日期:2003.5.1
Using an Ir-f-Binaphane complex as the catalyst, complete conversions and high enantioselectivies (up to 96% ee) were achieved in the asymmetric reductive amination of aryl ketones in the presence of Ti(O(i)()Pr)(4) and I(2). A simple and efficient method of synthesizing chiral primary amines has been realized.
AlCl3 has been employed for highly chemoselectivereductive amination of carbonylcompounds in ethanol using polymethylhydrosiloxane as an inexpensive, stable and safe reducingagent without an inert atmosphere. A large range of functional groups such as nitro, carboxylic acid, acetyl, nitrile, halogen, methoxy, alkene and heterocycles were well tolerated. AlCl3 also catalyzed tandem amination–amidation
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 formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures
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which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
Ligand-free Iron(II)-Catalyzed N-Alkylation of Hindered Secondary Arylamines with Non-activated Secondary and Primary Alcohols <i>via</i>
a Carbocationic Pathway
作者:Onkar S. Nayal、Maheshwar S. Thakur、Manoranjan Kumar、Neeraj Kumar、Sushil K. Maurya
DOI:10.1002/adsc.201701183
日期:2018.2.15
Secondary benzylic alcohols represent a challenging class of substrates for N‐alkylation of amines. Herein, we describe an iron(II)‐catalyzed eco‐friendly protocol for N‐alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of the known borrowinghydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self‐condensation