Electrochemical Synthesis of Biaryls via Oxidative Intramolecular Coupling of Tetra(hetero)arylborates
作者:Arif Music、Andreas N. Baumann、Philipp Spieß、Allan Plantefol、Thomas C. Jagau、Dorian Didier
DOI:10.1021/jacs.9b12300
日期:2020.3.4
scope, scalability and robustness of this unconventional catalyst-free transformation, leading to functional-ized biaryls and ultimately furnishing drug-like small molecules as well as late stage derivatization of natural compounds. In addition, the observed selectivity of the oxidative coupling reaction is related to the electronic structure of the TABs through quantum-chemical calculations and experimental
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
Stereoconvergent Arylations and Alkenylations of Unactivated Alkyl Electrophiles: Catalytic Enantioselective Synthesis of Secondary Sulfonamides and Sulfones
作者:Junwon Choi、Pablo Martín-Gago、Gregory C. Fu
DOI:10.1021/ja506885s
日期:2014.8.27
controlling the stereochemistry of the sulfur-bearing carbon of such targets. In this report, we describe nickel-catalyzed stereoconvergent Negishi arylations and alkenylations of racemic α-bromosulfonamides and -sulfones that furnish the desired cross-coupling product in very good ee and yield for an array of reaction partners. Mechanistic studies are consistent with the generation of a radical intermediate
开发用于生成对映体富集的磺酰胺和砜的有效方法是有机合成和药物化学等领域的重要目标;然而,关于直接催化不对称方法来控制此类目标的含硫碳的立体化学的报道相对较少。在本报告中,我们描述了镍催化的立体收敛 Negishi 芳基化和外消旋 α-溴磺酰胺和 - 砜的烯基化,它们以非常好的 ee 和产率为一系列反应伙伴提供所需的交叉偶联产物。机理研究与自由基中间体的产生一致,该中间体具有足够的寿命以扩散出溶剂笼并环化到侧链烯烃上。
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
Arylzinc Halides by Silver Catalyzed Zinc Insertion into Aryl Iodides
作者:Gianluca Casotti、Anna Iuliano、Adriano Carpita
DOI:10.1002/ejoc.201801543
日期:2019.2.7
A catalytic amount of silver acetate efficiently promotes direct insertion of zinc metal into aryl iodides, having different structure, in ethereal solvent. Electron‐rich substrates also rapidly undergo oxidative metalation. The arylzinc iodides formed give Negishi coupling products under mild reaction conditions.