Catalytic hunsdiecker reaction of alpha,beta-unsaturated carboxylic acids: how efficient is the catalyst?

Jaya Prakash Das; Sujit Roy

doi:10.1021/jo025868h

Catalytic hunsdiecker reaction of alpha,beta-unsaturated carboxylic acids: how efficient is the catalyst?

J Org Chem. 2002 Nov 1;67(22):7861-4. doi: 10.1021/jo025868h.

Authors

Jaya Prakash Das¹, Sujit Roy

Affiliation

¹ Organometallics & Catalysis Laboratory, Chemistry Department, Indian Institute of Technology, Kharagpur 721302, India.

PMID: 12398515
DOI: 10.1021/jo025868h

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.