complex presented higher reactivity in the transferhydrogenation (TH) of ketones in 2-propanol. Experimentally, it was established that both the benzimidazole and amine N–H proton played a vital role in the enhancement of the catalytic activity. Utilizing this system a wide range of aldehydes and ketones were reduced efficiently. Notably, the TH of several imines, as well as chemoselective reduction of
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.
Abstract A series of novel [3]ferrocenophane-derived N/BfrustratedLewispairs (FLPs) were synthesized and successfully applied to the catalytic hydrogenation of imines in 71-93% yields. This approach could be easily conducted on gram scale and provided versatile synthetic route for the key intermediate of sertraline hydrochloride without heavy metal residues. Graphical Abstract
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.