Chiral-at-metal iridium complex for efficient enantioselective transfer hydrogenation of ketones
作者:Cheng Tian、Lei Gong、Eric Meggers
DOI:10.1039/c6cc00972g
日期:——
A bis-cyclometalated iridium(III) complex with metal-centered chirality catalyzes the enantioselectivetransferhydrogenation of ketones with high enantioselectivities at low catalyst loadings down to 0.002 mol%. Importantly, the rate of catalysis...
Chiral AlIII-calixarene complexes were investigated as catalysts for the asymmetric Meerwein–Ponndorf–Verley (MPV) reduction reaction when using chiral and achiral secondary alcohols as reductants. The most enantioselective catalyst consisted of a new axially chiral vaulted-hemispherical calix[4]arene phosphite ligand, which attained an enantioselective excess of 99%. This ligand consists of two lower-rim
Highly Enantioselective Cobalt-Catalyzed Hydroboration of Diaryl Ketones
作者:Wenbo Liu、Jun Guo、Shipei Xing、Zhan Lu
DOI:10.1021/acs.orglett.0c00293
日期:2020.4.3
A highlyenantioselective cobalt-catalyzed hydroboration of diaryl ketones with pinacolborane was developed using chiral imidazole iminopyridine as a ligand to access chiral benzhydrols in good to excellent yields and ee. This protocol could be carried out in a gram scale under mild reaction conditions with good functional group tolerance. Chiral biologically active 3-substituted phthalide and (S)-neobenodine
作者:Rick C. Betori、Catherine M. May、Karl A. Scheidt
DOI:10.1002/anie.201909426
日期:2019.11.11
molecules. Direct C−H oxyfunctionalization, or the one step conversion of a C−H bond to a C−O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single‐flask photoredox/enzymatic process for direct C−H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity
For the enantioselective borohydride reduction of carbonyl compounds catalyzed by the optically active ketoiminatocobalt complexes, chloroform has been employed as a unique solvent for achieving a high enantioselectivity, whereas it was found that a catalytic amount of chloroform effectively activated the present catalytic system to convert various ketones into the corresponding reduced product with a high ee in the THF solvent.