68723-25-1Relevant articles and documents
Sterically Hindered Ketones via Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling of Amides by N-C(O) Activation
Liu, Chengwei,Lalancette, Roger,Szostak, Roman,Szostak, Michal
supporting information, p. 7976 - 7981 (2019/10/10)
Herein, we report a new protocol for the synthesis of sterically hindered ketones 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 studies provide insight into ground-state distortion of sterically hindered amides and show that ortho-substitution alleviates the N-C(O) bond twist.
Selective synthetic routes to sterically hindered unsymmetrical diaryl ketones via arylstannanes
Lo Fiego, Marcos J.,Silbestri, Gustavo F.,Chopa, Alicia B.,Lockhart, Maria T.
experimental part, p. 1707 - 1714 (2011/05/17)
Bulky arylstannanes and 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); and (iii) a solvent-free, indium-promoted procedure. A radical mechanism is proposed for the indium-mediated reactions.2011 American Chemical Society.
Palladium-phosphinous acid-catalyzed cross-coupling of aryl and acyl halides with aryl-, alkyl-, and vinylzinc reagents
Xu, Hanhui,Ekoue-Kovi, Kekeli,Wolf, Christian
, p. 7638 - 7650 (2008/12/22)
(Chemical Equation Presented) Several palladium-phosphinous acids have been prepared and employed in cross-coupling reactions of aryl or acyl halides with aliphatic and aromatic organozinc reagents. The POPd7-catalyzed reaction of aryl halides, including electron-rich aryl chlorides, and arylzinc reagents was found to afford biaryls exhibiting alkoxy, alkylthio, amino, ketone, cyano, nitro, ester, and heteroaryl groups in 75-93% yield. Excellent results were obtained with sterically hindered substrates which gave di- and tri-ortho-substituted biaryls in up to 92% yield. Aryl halides also undergo POPd7-catalyzed aryl-vinyl and aryl-alkyl bond formation under mild conditions. Styrenes and alkylarenes were prepared in 79-93% yield from aryl halides and vinyl or alkylzinc reagents. The replacement of aryl halides by acyl halides provides access to ketones which were produced in up to 98% yield when POPd was used as catalyst. This approach overcomes the limited substrate scope, reduced regiocontrol, and low functional group tolerance of traditional Friedel-Crafts acylation methods.