Primary Amines by Transfer Hydrogenative Reductive Amination of Ketones by Using Cyclometalated Ir<sup>III</sup>Catalysts
作者:Dinesh Talwar、Noemí Poyatos Salguero、Craig M. Robertson、Jianliang Xiao
DOI:10.1002/chem.201303541
日期:2014.1.3
Cyclometalated iridiumcomplexes are found to be versatile catalysts for the direct reductive amination (DRA) of carbonyls to give primary amines under transfer‐hydrogenation conditions with ammonium formate as both the nitrogen and hydrogen source. These complexes are easy to synthesise and their ligands can be easily tuned. The activity and chemoselectivity of the catalyst towards primary amines
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
Levulinic acid (LA) is transformed into pyrrolidinones via iridium-catalysed reductive amination using formic acid as the hydrogen source under aqueous conditions. The catalytic system is the most active and performs under the mildest conditions ever reported for the reductive amination of LA.
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.
Palladium-Catalyzed Aerobic Oxidative Cyclization of <i>N</i>-Aryl Imines: Indole Synthesis from Anilines and Ketones
作者:Ye Wei、Indubhusan Deb、Naohiko Yoshikai
DOI:10.1021/ja3030824
日期:2012.6.6
We report here an operationally simple, palladium-catalyzed cyclization reaction of N-aryl imines, affording indoles via the oxidative linkage of two C-H bonds under mild conditions using molecular oxygen as the sole oxidant. The process allows quick and atom-economical assembly of indole rings from inexpensive and readily available anilines and ketones and tolerates a broad range of functional groups