Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization
摘要:
A copper(11)-catalyzed oxidative cyclization of enamides to oxazoles via vinylic C-H bond functionalization at room temperature is described. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in moderate to high yields. This reaction protocol is complementary to our previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization
摘要:
A copper(11)-catalyzed oxidative cyclization of enamides to oxazoles via vinylic C-H bond functionalization at room temperature is described. Various 2,5-disubstituted oxazoles bearing aryl, vinyl, alkyl, and heteroaryl substituents could be synthesized in moderate to high yields. This reaction protocol is complementary to our previously reported iodine-mediated cyclization of enamides to afford 2,4,5-trisubstituted oxazoles.
Mild and General Conditions for Negishi Cross-Coupling Enabled by the Use of Palladacycle Precatalysts
作者:Yang Yang、Nathan J. Oldenhuis、Stephen L. Buchwald
DOI:10.1002/anie.201207750
日期:2013.1.7
A wide range of biaryls were synthesized by palladium‐catalyzed Negishi cross‐couplings at ambient temperature or with low catalyst loading. This protocol features the use of a recently reported aminobiphenyl palladacycleprecatalyst to generate the catalytically active XPhosPd0 species. Significantly, a wide range of challenging heterocyclic and polyfluorinated aromatic substrates can be employed