An N-heterocyclic carbene iridium catalyst with metal-centered chirality for enantioselective transfer hydrogenation of imines

作者：Li, Yanjun; Lei, Meng; Yuan, Wei; Meggers, Eric; Gong, Lei^*

来源：Chemical communications, 2017, 53(57): 8089-8092.

DOI：10.1039/c7cc04691j

• ASYMMETRIC TRANSFER HYDROGENATION
• ALPHA,BETA-UNSATURATED 2-ACYL IMIDAZOLES
• COMPLEXES
• KETIMINES
• KETONES
• ACID
• SELECTIVITY
• REDUCTION
• ALDEHYDES
• LIGANDS

A cyclometalating N-heterocyclic carbene iridium complex featuring metal-centered chirality was designed and used for the asymmetric transfer hydrogenation (ATH) of imines. Four strongly sigma-donating carbon-based substituents (2 carbenes and 2 phenyl moieties), a chirality transfer directly from the stereogenic metal center to the C=N bond of substrates, as well as a restriction of catalyst deactivation by steric demanding substituents, render the new complex one of the most efficient catalysts for ATH of cyclic N-sulfonylimines ( down to 0.01 mol% cat., 24 examples, 94-98% ee).

• 出版日期2017-7-21
• 单位厦门大学