Nickel‐Catalyzed α‐Carbonylalkylarylation of Vinylarenes: Expedient Access to γ,γ‐Diarylcarbonyl and Aryltetralone Derivatives
作者:Shekhar KC、Roshan K. Dhungana、Namrata Khanal、Ramesh Giri
DOI:10.1002/anie.201913435
日期:2020.5.18
We report a Ni-catalyzed regioselective α-carbonylalkylarylation of vinylarenes with α-halocarbonyl compounds and arylzinc reagents. The reaction works with primary, secondary and tertiary α-halocarbonyl molecules, and electronically varied arylzinc reagents. The reaction generates γ,γ-diarylcarbonyl derivatives with α-secondary, tertiary and quaternary carbon centers. The products can be readily converted
Nickel-Promoted Alkylative or Arylative Carboxylation of Alkynes
作者:Masanori Takimoto、Kazuya Shimizu、Miwako Mori
DOI:10.1021/ol016585z
日期:2001.10.1
terminal alkynes via a carbondioxide fixation process was investigated. In the presence of a stoichiometric amount of a zero-valent nickel complex, the reaction of alkynes with CO2 gave a nickelacycle, which was reacted with various organozinc reagents under very mild conditions to provide beta,beta'-disubstituted, alpha,beta-unsaturated carboxylic acids in a highlyregio- and stereoselective manner
Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts
作者:Prakash Basnet、Shekhar KC、Roshan K. Dhungana、Bijay Shrestha、Timothy J. Boyle、Ramesh Giri
DOI:10.1021/jacs.8b09401
日期:2018.11.21
We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective γ,δ-diarylation of unactivated alkenes in simple ketimines with aryl halides and arylzinc reagents. The bimetallic synergy, which generates cationic Ni(II) species during reaction, promotes migratory insertion and transmetalation steps and suppresses β-H elimination and cross-coupling, the major side reactions
Stabilised arylzinc iodide, prepared by direct insertion of zinc into aryl iodides, were used as nucleophiles in the Hayashi Rh‐catalysed enantioselective conjugateaddition to enones. The reaction conditions were optimized in the addition of phenylzinc iodide to 2‐cyclohexen‐1‐one, obtaining good yields and 99% ee of the addition product. The general applicability of the protocol was checked using
Ni-Catalyzed Regioselective Alkylarylation of Vinylarenes via C(sp<sup>3</sup>)–C(sp<sup>3</sup>)/C(sp<sup>3</sup>)–C(sp<sup>2</sup>) Bond Formation and Mechanistic Studies
作者:Shekhar KC、Roshan K. Dhungana、Bijay Shrestha、Surendra Thapa、Namrata Khanal、Prakash Basnet、Robert W. Lebrun、Ramesh Giri
DOI:10.1021/jacs.8b05374
日期:2018.8.8
We report a Ni-catalyzed regioselective alkylarylation of vinylarenes with alkylhalides and arylzinc reagents to generate 1,1-diarylalkanes. The reaction proceeds well with primary, secondary and tertiary alkylhalides, and electronically diverse arylzinc reagents. Mechanistic investigations by radical probes, competition studies and quantitative kinetics reveal that the current reaction proceeds