Enantioselective addition of ArTi(O<sup>i</sup>Pr)<sub>3</sub> to aldehydes catalyzed by a titanium complex of an N-sulfonylated amino alcohol
作者:Shih-Ju Chang、Shuangliu Zhou、Han-Mou Gau
DOI:10.1039/c4ra14173c
日期:——
additions of ArTi(OiPr)3 to aldehydescatalyzed by a titaniumcatalyst of N-sulfonylated aminoalcohols were reported, and results showed that the chiral N-sulfonylated aminoalcohol with two stereogenic centers could catalyze the asymmetric addition of ArTi(OiPr)3 to aldehydes to afford desired secondary alcohols in good yields with good to excellent enantioselectivities of up to 95% ee.
报道了N-磺酰化氨基醇的钛催化剂催化醛基上不对称地添加ArTi(O i Pr)3,结果表明具有两个立体中心的手性N-磺酰化氨基醇可以催化ArTi(O)的不对称加成。i Pr)3-醛,以高收率提供所需的仲醇,并具有高达95%ee的良好至优异的对映选择性。
Chiral Lithium Amido Aryl Zincates: Simple and Efficient Chemo‐ and Enantio‐Selective Aryl Transfer Reagents
作者:Pauline Chaumont‐Olive、Mathieu Rouen、Gabriella Barozzino‐Consiglio、Amel Ben Abdeladhim、Jacques Maddaluno、Anne Harrison‐Marchand
DOI:10.1002/anie.201813510
日期:2019.3.4
An enantioselective aryl transfer is promoted using chiral tricoordinated lithium amido aryl zincates that are easily accessible reagents and whose chiral appendage is simply recovered for reuse. The arylation reaction is run in good yields (60 % average on twenty substrates) and high enantiomericexcesses (95 % ee average). This occurs whatever the ortho, meta, or para substituent borne by the substrate
Chiral C₂-symmetric diamines have emerged as versatile auxiliaries or ligands in numerous asymmetric transformations. Chiral 2,2'-bispyrrolidine-based salan ligands were prepared and applied to the asymmetric aryltransfer to aldehydes with arylboronic acids as the source of transferablearyl groups. The corresponding diarylmethanols were obtained in high yields with moderate to good enantioselectivitives
手性 C 2 对称二胺已成为众多不对称转化中的通用助剂或配体。制备了基于手性 2,2'-双吡咯烷的 Salan 配体,并将其应用于以芳基硼酸作为可转移芳基来源的醛的不对称芳基转移。相应的二芳基甲醇以高产率获得,对映选择性高达 83% ee。
Enantioselective Reduction of Diaryl Ketones Catalyzed by a Carbonyl Reductase from<i>Sporobolomyces salmonicolor</i>and its Mutant Enzymes
作者:Hongmei Li、Dunming Zhu、Ling Hua、Edward R. Biehl
DOI:10.1002/adsc.200900045
日期:2009.3
Abstractmagnified imageThe carbonyl reductase from red yeast Sporobolomyces salmonicolor AKU4429 (SSCR) and its mutant enzymes effectively catalyzed the enantioselective reduction of diaryl ketones to give the corresponding chiral alcohols. Both conversion and enantioselectivity were dependent on the co‐solvent in the reaction medium. Diaryl ketones with a para‐substituent on one of the phenyl groups were reduced with high enantioselectivity (up to 99% ee), which is difficult to achieve using chemical methods such as chiral borane reduction, asymmetric hydrogenation or hydrosilylation. Mutation of SSCR at Q245 resulted in a higher amount of (S)‐enantiomer in the products, and in the case of mutant Q245P with para‐substituted diaryl ketones as substrate, this effect was so remarkable that the reduction enantiopreference was switched from (R) to (S). The present study provides valuable information about the catalytic properties of the carbonyl reductase SSCR toward the reduction of diaryl ketones, serving as basis for further engineering of this enzyme to develop efficient biocatalysts for highly enantiospecific reduction of diaryl ketones without high electronic dissymmetry or an ortho‐substituent on one of the aryl groups.