Platinum-Catalyzed Intramolecular Vinylchalcogenation of Alkynes with β-Phenylchalcogeno Conjugated Amides
摘要:
Platinum-catalyzed intramolecular vinylthiolation and -selenation of internal alkynes with vinylchalcogenides 1 having a carbamoyl group on cis-beta-position of vinyl moiety was developed. The conjugated six-membered lactam framework 2 was constructed in 1 high yields. Density functional theory calculations for alkyne insertion processes suggest seven-membered platinacycle 3 is a kinetically favored intermediate of this catalytic system.
Organylzinc Chalcogenolate Promoted Michael-Type Addition of α,β-Unsaturated Carbonyl Compounds
作者:Vanessa Lóren Nunes、Ingryd Cristina de Oliveira、Olga Soares do Rêgo Barros
DOI:10.1002/ejoc.201301497
日期:2014.3
chalcogenide compounds promoted by organylzinc chalcogenolates. In this protocol, reductive cleavage of diorganyl dichalcogenide bonds by the Zn/NH4OH system led to organylzinc chalcogenolates. The reaction was performed with propiolic acids and esters and afforded β-organochalcogenacrylic acids and esters under mild basic conditions. The stereochemistry corresponded to anti-Markovnikov addition of the organyl
Platinum-catalyzed intramolecular vinylthiolation and -selenation of internal alkynes with vinylchalcogenides 1 having a carbamoyl group on cis-beta-position of vinyl moiety was developed. The conjugated six-membered lactam framework 2 was constructed in 1 high yields. Density functional theory calculations for alkyne insertion processes suggest seven-membered platinacycle 3 is a kinetically favored intermediate of this catalytic system.