Nonenzymatic kinetic resolution of racemic 2,2,2-trifluoro-1-aryl ethanol via enantioselective acylation
作者:Qing Xu、Hui Zhou、Xiaohong Geng、Peiran Chen
DOI:10.1016/j.tet.2009.01.058
日期:2009.3
Kineticresolution of a series of 2,2,2-trifluoro-1-aryl ethanol with (R)-benzotetramisole as the catalyst has been investigated. The result showed that when the aryl group in the substrate was a phenyl (or a phenyl substituted by an electron-donating group) or a naphthyl (an extended phenyl) group, the system could give an s value higher than 20. Preparative KR examples demonstrated the applicability
α,α,α-Trifluoroacetophenone (2), which is susceptible to noncatalytic reduction by BH3, could be reduced to chiral alcohol up to 90% ee by using electronically tuned-CBS catalyst (1) with BH3. The enantioselectivities highly correlated with the differential orbital energies between 1–BH3 adduct and 2, which were calculated by DFT method.
Chemo- and Enantioselective Addition and β-Hydrogen Transfer Reduction of Carbonyl Compounds with Diethylzinc Reagent in One Pot Catalyzed by a Single Chiral Organometallic Catalyst
作者:Huayin Huang、Hua Zong、Guangling Bian、Ling Song
DOI:10.1021/acs.joc.5b01871
日期:2015.12.18
as the catalyst, the asymmetric β-H transfer reduction of aromatic α-trifluoromethyl ketones and enantioselective addition of aromatic aldehydes with Et2Zn in one pot were successfully realized, affording the corresponding additive products of secondary alcohols in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee) and the reduction products of α-trifluoromethyl alcohols in good
The asymmetric hydrogenation of 2,2,2-trifluoroacetophenones and aryl perfluoroalkyl ketones was developed using a unique, well-defined chloride-bridged dinuclear rhodium(III) complex bearing Josiphos-type diphosphine ligands. These complexes were prepared from [RhCl(cod)]2 , Josiphos ligands, and hydrochloric acid. As catalyst precursors, they allow for the efficient and enantioselective synthesis
Asymmetric trifluoromethylation of aromatic aldehydes by cooperative catalysis with (IPr)CuF and quinidine-derived quaternary ammonium salt
作者:Shaoxiang Wu、Wei Zeng、Qi Wang、Fu-Xue Chen
DOI:10.1039/c2ob26827b
日期:——
A general enantioselective trifluoromethylation of aldehydes has been developed using (IPr)CuF and quinidine-derived quaternary ammonium salt as the cooperative catalyst. Thus, a wide range of aromatic aldehydes have been converted to the corresponding products in up to 92% yield and 81% ee at 2 mol% of catalyst loading. The greatly enhanced activity and enantioselectivity result from the initiative generation of active [(IPr)CuCF3] as well as additional coordination activation of other copper species.