90992-12-4Relevant articles and documents
SYNTHESIS OF ISOCOUMARINS VIA THALLATION-OLEFINATION OF BENZOIC ACIDS
Larock, R. C.,Varaprath, S.,Lau, H. H.,Fellows, C. A.
, p. 5274 - 5284 (2007/10/02)
Benzoic acid and substituted benzoic acids are readily thallated by thallium(III) trifluoroacetate and subsequently reacted with palladium chloride and simple olefins, allylic halides, vinyl halides, or vinyl esters to give isocoumarins.The organic halide reactions are catalytic in palladium. 1,2- and 1,3-dienes also react catalytically to afford 4-alkylidene- and 3-vinyl-3,4-dihydroisocoumarins, respectively.Vinylcyclopropanes also afford 3-vinyl-3,4-dihydroisocoumarins.This highly convenient thallation-olefination approach appears quite general for the synthesis of isocoumarins.