Understanding Halide Counterion Effects in Enantioselective Ruthenium-Catalyzed Carbonyl (α-Aryl)allylation: Alkynes as Latent Allenes and Trifluoroethanol-Enhanced Turnover in The Conversion of Ethanol to Higher Alcohols via Hydrogen Auto-transfer
作者:Eliezer Ortiz、Jonathan Z. Shezaf、Yu-Hsiang Chang、Théo P. Gonçalves、Kuo-Wei Huang、Michael J. Krische
DOI:10.1021/jacs.1c07857
日期:2021.10.13
preference that defines metal-centered stereogenicity and, therefrom, the enantioselectivity of C−C coupling in ruthenium-catalyzed anti-diastereo- and enantioselective C−C couplings of primary alcohols with 1-aryl-1-propynes to form products of carbonyl anti-(α-aryl)allylation. Computational studies reveal that a non-classical hydrogen bond between iodide and the aldehyde formyl CH bond stabilizes the favored
RuX(CO)(η 3 -C 3 H 5 )(JOSIPHOS)(其中 X = Cl、Br 或 I)的晶体学表征揭示了卤化物依赖性非对映异构体偏好,定义了以金属为中心的立体异构性,并由此定义了钌催化的伯醇与 1-芳基-1-丙炔的反非对映和对映选择性 CC 偶联中的 CC 偶联,形成羰基反-(α-芳基)烯丙基化的产物。计算研究表明,碘化物和醛甲酰基 CH 键之间的非经典氢键稳定了羰基加成所需的过渡态。开发了一种改进的催化系统,该系统采用含碘化物预催化剂 RuI(CO) 3 (η 3 -C 3 H 5 ) 与三氟乙醇结合,实现了以前无法实现的转化,如第一个对映选择性钌催化的 CC 所示乙醇偶联生成高级醇。
Rapid Access to Highly Functionalized Alkyl Boronates by NiH‐Catalyzed Remote Hydroarylation of Boron‐Containing Alkenes
作者:Yao Zhang、Bo Han、Shaolin Zhu
DOI:10.1002/anie.201907185
日期:2019.9.23
selective functionalization of relatively simple and readily accessible precursors to produce highlyfunctionalizedalkylboronates is a synthetically useful process. Herein we report a NiH-catalyzed remotehydroarylation process that can, through a synergistic combination of chain walking and subsequent cross-coupling, introduce an aryl group at the adjacent carbon atom of alkylboronates under mild