The branched, chiral products 1 are formed preferentially in the allylicalkylations in Equation (1) when the Pd catalyst contains the P,N ligand L* or derivatives thereof. The ligands are readily synthesized from commercially available precursors.
nickel and chiralamine cooperative catalysis to enable a highlyenantioselectiveallylic alkylation reaction between α-branched aldehydes and a wide scope of allyl esters, allowing the all-carbon quaternary stereocenter to be accessed with excellent enantioselectivity (up to 98% ee) and structural diversity. The general synthetic applicability has been showcased by the enantioselective synthesis of
全碳四元立体中心构成了天然产物和生物活性化合物的重要组成部分。在这里,我们公开了一种镍和手性胺协同催化,使 α-支化醛和各种烯丙基酯之间发生高度对映选择性的烯丙基烷基化反应,从而以优异的对映选择性(高达 98% ee ) 和结构多样性。关键手性构件的对映选择性合成以获取 (+)-依他佐辛、(-)-aphanorphine 和其他两种生物活性化合物,展示了一般合成适用性。
Kinetic Resolution of Racemic and Branched Monosubstituted Allylic Acetates by a Ruthenium-Catalyzed Regioselective Allylic Etherification
of racemic and branched monosubstituted allylicacetates by a ruthenium-catalyzed regioselective allylic etherification. The reaction was effectively catalyzed by the chiral ruthenium catalyst, which was generated by [RuCl2(p-cymene)]2 and (S,S)-iPr-pybox and a catalytic amount of TFA, and both the allylic etherification product and recovered allylicacetate were obtained as an enantiomerically enriched
for generation of Pd/phosphite-oxazoline catalysts containing an alkyl backbone chain has been successfully applied to Pd-catalyzed allylicsubstitution reactions. By carefully selecting the substituents at both the alkyl backbone chain and the oxazoline of the ligand, as well as the configuration of the biaryl phosphite group, high activities (TOF > 8000 mol substrate × (mol Pd × h)−1) and excellent
Ni-Catalyzed Enantioselective Allylic Alkylation of <i>H</i>-Phosphinates
作者:Qing Zhang、Xu-Teng Liu、Yue Wu、Qing-Wei Zhang
DOI:10.1021/acs.orglett.1c02986
日期:2021.11.19
The asymmetric synthesis of P-stereogenic phosphinates through allylicalkylation of H-phosphinates has been developed. With H-phosphinates and allylic acetates as the starting materials, a variety of allylic P-chiral phosphinates were accessed in high enantioselectivities of up to 92% ee and generally high yields. In addition, a further study demonstrated the applicability of this protocol, including
的不对称合成P -stereogenic次膦酸盐通过的烯丙基烷基化ħ -phosphinates已经研制成功。以H-次膦酸盐和烯丙基乙酸酯为起始材料,以高达 92% ee 的高对映选择性和通常高产率获得了多种烯丙基P-手性次膦酸盐。此外,进一步的研究证明了该协议的适用性,包括在温和的反应条件下,使用有机锂试剂将手性产物从次膦酸盐放大合成和轻松转化为氧化膦。