Enantioselective β-Protonation by a Cooperative Catalysis Strategy
摘要:
An enantioselective N-hetetoeyclic carbene (NHC)-catalyzed beta-protonation through the orchestration of three distinct organocatalysts has been developed. This cooperative catalyst system enhances both yield and selectivity, compared to only the NHC-catalyzed process. This new method allows for the,efficient conversion of a large scope of aryl-oxobutenoates to highly enantioenriched succinate derivatives and demonstrates the benefits of combining different activation modes in organocatalysis.
Palladium-Catalyzed Asymmetric Hydroesterification of α-Aryl Acrylic Acids to Chiral Substituted Succinates
作者:Xiaolei Ji、Chaoren Shen、Xinxin Tian、Kaiwu Dong
DOI:10.1021/acs.orglett.1c03361
日期:2021.11.5
A palladium-catalyzed asymmetric hydroesterification of α-aryl acrylic acids with CO and alcohol was developed, preparing a variety of chiral α-substituted succinates in moderate yields with high ee values. The kinetic profile of the reaction progress revealed that the alkene substrate first underwent the hydroesterification followed by esterification with alcohol. The origin of the enantioselectivity
开发了钯催化的 α-芳基丙烯酸与 CO 和醇的不对称加氢酯化反应,以中等收率和高ee值制备了多种手性 α-取代琥珀酸酯。反应过程的动力学曲线表明,烯烃底物首先进行加氢酯化,然后与醇进行酯化。通过密度泛函理论计算阐明了对映选择性的起源。
Catalytic, Enantioselective β-Protonation through a Cooperative Activation Strategy
作者:Michael H. Wang、David Barsoum、C. Benjamin Schwamb、Daniel T. Cohen、Brian C. Goess、Matthias Riedrich、Audrey Chan、Brooks E. Maki、Rama K. Mishra、Karl A. Scheidt
DOI:10.1021/acs.joc.7b00334
日期:2017.5.5
only feasible, but also adaptable to a kinetic resolution of secondaryalcohols through NHC-catalyzed acylation. In-depth analysis of this process determined that careful catalyst and solvent pairing is critical for optimal yield and selectivity; proper choice of nonpolar solvent provided improved yield through suppression of an oxidative side reaction, while employment of a cooperative catalytic approach
Preparation of Chiral 3-Arylpyrrolidines via the Enantioselective 1,4-Addition of Arylboronic Acids to Fumaric Esters Catalyzed by Rh(I)/Chiral Diene Complexes
A highly efficient rhodium-catalyzed protocol for the preparation of 2-arylsuccinic esters and 3-arylpyrrolidines of high optical purity has been achieved. In the presence of 1 mol % of a chiral diene/Rh(I) catalyst, asymmetric addition of various arylboronic acids to di-fert-butyl fumarate (3c) provides the corresponding adducts in up to 99% yield and 94 -> 99.5% ee. Excellent enantioselectivities were also observed in the regio- and enantioselective conjugate addition of phenylboronic acid (4a) to compound 3e.
Wren; Williams, Journal of the Chemical Society, 1916, vol. 109, p. 580