protocol for the synthesis of sterically hinderedketones that proceeds via palladium-catalyzed Suzuki–Miyaura cross-coupling of unconventional amide electrophiles by selective N–C(O) activation. Mechanistic studies demonstrate that steric bulk on the amide has a major impact, which is opposite to the traditional Suzuki–Miyaura cross-coupling of sterically hindered aryl halides. Structural and computational
Arylation of Aldehydes To Directly Form Ketones via Tandem Nickel Catalysis
作者:Chuanhu Lei、Daoyong Zhu、Vicente III Tiu Tangcueco、Jianrong Steve Zhou
DOI:10.1021/acs.orglett.9b01782
日期:2019.8.2
both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination
Selective Synthetic Routes to Sterically Hindered Unsymmetrical Diaryl Ketones via Arylstannanes
作者:Marcos J. Lo Fiego、Gustavo F. Silbestri、Alicia B. Chopa、María T. Lockhart
DOI:10.1021/jo102366q
日期:2011.3.18
bulky aroyl chlorides are good reaction partners for the synthesis of two-, three-, and even four-ortho-substituted benzophenones, in good to excellent isolated yields (47−91%). Three simple and direct routes, with differential advantages, are proposed: (i) a catalyst-free protocol, in o-dichlorobenzene (ODCB) at 180 °C; (ii) a room temperature protocol, using AlCl3 (0.5 equiv), in dichloromethane (DCM);