Transition-Metal-Free Iodine Catalyzed Selenocayanation of Styrenyl Bromides and an Easy Access to Benzoselenophenes via Intermediacy of Styrenyl Selenocyanate
作者:Pintu Maity、Bidisha Paroi、Brindaban C. Ranu
DOI:10.1021/acs.orglett.7b02571
日期:2017.11.3
convenient procedure has been developed for the synthesis of styrenyl selenocyanates and benzoselenophenes from readily available styrenyl bromides by reaction with potassium selenocyanate in the presence of iodine under specified conditions. A series of both compounds have been obtained by this procedure. The synthesis of styrenyl selenocyanates has not been previously reported, and thus this method is of
Cooperative <i>N</i>-Heterocyclic Carbene/Palladium-Catalyzed Umpolung 1,4-Addition of Vinyl Bromides to Enals
作者:Bo Ling、Wenjun Yang、Yan-En Wang、Jianyou Mao
DOI:10.1021/acs.orglett.0c03654
日期:2020.12.18
A highly stereoselective umpolung 1,4-addition of vinylbromides to enals is enabled by NHC/palladium cooperative catalysis, generating various valuable γ,δ-unsaturated carbonyl derivatives in excellent yields (up to 90%). A detailed mechanism investigation indicates the NHC act as both organocatalyst and ligand for palladium during this system.
Room Temperature Copper(II)-Catalyzed Oxidative Cyclization of Enamides to 2,5-Disubstituted Oxazoles via Vinylic C–H Functionalization
作者:Chi Wai Cheung、Stephen L. Buchwald
DOI:10.1021/jo301332s
日期:2012.9.7
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.