Synthesis of Trisubstituted Isoxazoles by Palladium(II)-Catalyzed Cascade Cyclization–Alkenylation of 2-Alkyn-1-one <i>O</i>-Methyl Oximes
作者:Zhigang She、Dongyue Niu、Lei Chen、Maria A. Gunawan、Xhesika Shanja、William H. Hersh、Yu Chen
DOI:10.1021/jo300090k
日期:2012.4.6
palladium-catalyzed, cascade 5-endo-dig cyclization–alkenylation synthesis of isoxazoles has been developed. The addition of 1 equiv of n-Bu4NBr significantly increases the yield of the desired 4-alkenyl-3,4,5-trisubstituted isoxazoles. A variety of trisubstitutedisoxazoles are prepared in moderate to excellent yields. One example of the synthesis of a naphthoisoxazole is reported by a cascade cyclization–alkenylation-Heck
Cyclobutanones are synthetically versatile compounds that often require extensive effort to access. Herein, we report a facile synthesis of cyclobutanones based on the C(sp3)−H insertion chemistry of oxidatively generated gold carbenes. Various cyclobutanones were obtained in syntheticallyuseful yields from substrates with minimal structural prefunctionalization. This discovery reveals new synthetic utilities
作者:Sahaj Gupta、Jennifer A. Melanson、Louis Vaillancourt、William A. Nugent、Gerald J. Tanoury、Gabriele Schatte、Victor Snieckus
DOI:10.1021/acs.orglett.8b01300
日期:2018.7.6
The Pd-catalyzed regioselective C-H activation/arylation, /iodination, and/acetoxylation reactions of 4-arylpyrimidines using aryl iodides, N-iodosuccinimide, and (diacetoxyiodo)benzene respectively as coupling partners are described. Suzuki-Miyaura coupling and Sonogashira reactions of the resulting aryl iodides are demonstrated. The scalability of the C-H activation/functionalization starting with readily accessible 4-aryl pyrimidines is also reported.