Enantioselective Synthesis of Functionalized Arenes by Nickel‐Catalyzed Site‐Selective Hydroarylation of 1,3‐Dienes with Aryl Boronates
作者:Justin S. Marcum、Tiffany R. Taylor、Simon J. Meek
DOI:10.1002/anie.202004982
日期:2020.8.10
A catalytic method for the site‐selective and enantioselective synthesis of functionalized arenes by the intermolecular hydroarylation of terminal and internal 1,3‐dienes with aryl pinacolato boronates is reported. The reactions are promoted by 5.0 mol % of a readily available monodentate phosphoramidite‐Ni complex in ethanol, affording a variety of enantioenriched products in up to 96 % yield and
Transition metal-catalyzed dehydrogenation is a clean oxidation method requiring no additional oxidants. We have accomplished a heterogeneous Pd/C-catalyzed aqueous dehydrogenation of 1,4-cyclohexadienes and cyclohexenes to give the corresponding highly-functionalized arenes. Furthermore, various arenes could be efficiently constructed in a one-pot manner via a Diels–Alder reaction and the following
Photoinduced Palladium-Catalyzed Carbofunctionalization of Conjugated Dienes Proceeding via Radical-Polar Crossover Scenario: 1,2-Aminoalkylation and Beyond
作者:Kelvin Pak Shing Cheung、Daria Kurandina、Tetsuji Yata、Vladimir Gevorgyan
DOI:10.1021/jacs.0c03993
日期:2020.6.3
A photoinduced palladium-catalyzed 1,2-carbofunctionalization of conjugateddienes has been developed. This mild modular approach, which does not require employment of exogeneous photosensitizers and external oxidants, allows for efficient and highly regio- and ste-reoselective synthesis of a broad range of allylic amines from readily available 1,3-dienes, alkyl iodides, and amines. Employment of O-
additive-free, palladium-catalyzed asymmetric aminomethylative etherification of conjugated dienes that enables the efficient, asymmetric O-allylation of primary and secondary aliphatic alcohols as well as water. Mechanism studies revealed that the hydrogen-bonding interaction between the alcohol and the in situ introduced aminomethyl moiety is critical to facilitate the nucleophilic addition of the alcohol
Radical-Mediated Heck-Type Alkylation: Stereoconvergent Synthesis of Functionalized Polyenes
作者:Hong Zhang、Xinxin Wu、Yunlong Wei、Chen Zhu
DOI:10.1021/acs.orglett.9b02838
日期:2019.9.20
The stereospecific synthesis of polyenes is of great synthetic value. Disclosed herein is a new, efficient, stereoconvergent approach for the synthesis of functionalized polyenes via a radical-mediated Heck-type alkylation. The easily accessed Z- and E-mixed alkenes are harnessed as starting material, leading to a unique stereoisomer of polyenes. In addition, the transformation features mild reaction