Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of <i>vicinal</i>-dichlorides and chlorodienes
作者:Zhensheng Zhao、Graham K Murphy
DOI:10.3762/bjoc.14.67
日期:——
Allyl and vinyl chlorides represent important structural motifs in organic chemistry. Herein is described the chemoselective and regioselective reaction of aryl- and α-substituted phenylallenes with the hypervalent iodine (HVI) reagent 1-chloro-1,2-benziodoxol-3-one. The reaction typically results in vicinal dichlorides, except with proton-containing α-alkyl substituents, which instead give chlorinated
Enantioselective palladium-catalyzed diboration of 1,1-disubstituted allenes
作者:Jiawang Liu、Ming Nie、Qinghai Zhou、Shen Gao、Wenhao Jiang、Lung Wa Chung、Wenjun Tang、Kuiling Ding
DOI:10.1039/c7sc01254c
日期:——
A practical and enantioselectivepalladium-catalyzed diboration of 1,1-disubstituted allenes is developed by employing a P-chiral monophosphorus ligand BI-DIME to form a series of diboronic esters containing a chiral tertiary boronic ester moiety in excellent yields and ee’s with the palladium loading as low as 0.2 mol %. DFT calculations revealed a concerted mechanism of oxidative addition of bis(pinacolato)diboron
通过使用 P-手性单磷配体 BI-DIME 开发了一种实用且对映选择性的钯催化 1,1-二取代丙二烯二硼化反应,以形成一系列含有手性叔硼酸酯部分的二硼酸酯,具有优异的产率和与钯的 ee 值负载量低至 0.2 mol%。DFT 计算揭示了双(频哪醇)二硼和丙二烯插入的氧化加成的协同机制,以及对对映选择性起源的关键分散效应。该方法成功应用于芸苔唑的简洁、对映选择性合成。
Synthesis of Tetrahydroquinolines by Scandium-Catalyzed [3 + 3] Annulation of Anilines with Allenes and Dienes
作者:Xian Xu、Xizhou Zheng、Xin Xu
DOI:10.1021/acscatal.1c04657
日期:2021.12.17
Nickel-Catalyzed Regioselective Hydroalkynylation of Styrenes: Improved Catalyst System, Reaction Scope, and Mechanism
作者:Masamichi Shirakura、Michinori Suginome
DOI:10.1021/ol802475h
日期:2009.2.5
Addition of the sp-C-H bond of triisopropylsilylacetylene to the carbon-carbon double bonds of styrenes bearing functional groups proceeded efficiently at room temperature in the presence of 3 mol % of Ni(cod)(2) with a PMePh2 ligand. Use of 2-deuteriotriisopropylsilylacetylene in the hydroalkynylation of styrenes resulted in regioselective incorporation of deuterium into the beta-positions of recovered styrenes, along with its regioselective introduction into the product's methyl group.
Cobalt-Catalyzed Asymmetric Addition of Silylacetylenes to 1,1-Disubstituted Allenes
The asymmetric addition of silylacetylenes to 1,1-disubstituted allenes proceeded in the presence of a cobalt/chiral bisphosphine ligand to give the corresponding enynes with high enantioselectivity. The results of deuterium-labeling experiments indicated that a hydrogen atom at the chiral center is originated from the terminal alkyne, and they were in good agreement with the proposed catalytic cycle where enantioselectivity is determined by the reaction of the proposed pi-allylcobalt intermediate with the terminal alkyne.