title: Catalytic hunsdiecker reaction of alpha,beta-unsaturated carboxylic acids: how efficient is the catalyst?
abstract: UV-vis spectrophotometry is utilized to measure the relative efficiency of lithium acetate, tetrabutylammonium trifluoroacetate, and triethylamine as catalysts for the conversion of 4-methoxycinnamic acid to 4-methoxy-beta-bromostyrene. In acetonitrile-water as solvent, the efficiency order is lithium acetate > triethylamine > tetrabutylammonium trifluoroacetate. For triethylamine as catalyst, solvent-dependent order is acetonitrile-water > dichloromethane > acetonitrile. Using triethylamine as catalyst (5-20 mol %), cinnamic acids, and propiolic acids are converted to corresponding beta-bromostyrenes and 1-halo-1-alkynes in 60-98% isolated yields within 1-5 min.
authors.affiliation: Organometallics & Catalysis Laboratory, Chemistry Department, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: Jaya Prakash
authors.initials: JP
authors.lastname: Das
authors.forename: Sujit
authors.initials: S
authors.lastname: Roy