An N-heterocyclic carbene iridium catalyst with metal-centered chirality for enantioselective transfer hydrogenation of imines
作者:Yanjun Li、Meng Lei、Wei Yuan、Eric Meggers、Lei Gong
DOI:10.1039/c7cc04691j
日期:——
carbene iridium complex featuring metal-centered chirality was designed and applied to the asymmetric transfer hydrogenation (ATH) of imines. Four strongly σ-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
Catalytic Enantioselective Synthesis of 3-Substituted Benzosultams via Corey-Bakshi-Shibata Reduction of Cyclic N-Sulfonylimines
作者:Dieter Enders、Matthias Seppelt
DOI:10.1055/s-0030-1259314
日期:2011.2
The catalytic asymmetric synthesis of 3-substituted benzo-fused sultams employing the Corey-Bakshi-Shibata reduction with catecholborane of the corresponding cyclic N-sulfonylimines is reported. Good to excellent yields (74-95%) and enantiomeric excesses (69-94%) are obtained.
Asymmetric hydrosilylations of N-sulfonyl ketimines and vicinal diimines with chiral boranes
作者:Ting Liu、Xiangqing Feng、Haifeng Du
DOI:10.1016/j.tetlet.2022.154202
日期:2022.11
A metal-free hydrosilylation of N-sulfonyl ketimines under the FLP catalysis has been realized to give optically active amines in high yields with up to 73% ee. Significantly, a chiral borane-catalyzed asymmetrichydrosilylation of vicinal diimines was also achieved, affording the desired cis-1,2-diamines with 12–70% ee’s.
N-磺酰基酮亚胺在 FLP 催化下的无金属氢化硅烷化反应已经实现,以高收率得到光学活性胺,ee 高达 73%。值得注意的是,还实现了手性硼烷催化的邻位二亚胺的不对称氢化硅烷化,提供了所需的 ee 为 12-70% 的顺式-1,2-二胺。
The Proton of Alcohols as Hydrogen Source in Diboron-Mediated Nickel-Catalyzed Asymmetric Transfer Hydrogenation of Cyclic <i>N</i>-Sulfonyl Imines
The proton of alcohols as the sole hydrogensource in diboron-mediated nickel-catalyzed asymmetric transfer hydrogenation of cyclic N-sulfonyl imines has been developed, providing the chiral cyclic sulfamidates in excellent enantioselectivities. The mechanistic investigations suggested that the proton of alcohols could be activated by tetrahydroxydiboron to form active nickel hydride species.