Microwave-Enhanced Carbonylative Generation of Indanones and 3-Acylaminoindanones

摘要

The development of microwave-accelerated protocols for palladium(O)-catalyzed carbonylative cyclization of unsatur-ated aryl bromides and chlorides is described.By employing o-bromostyryl derivatives lacking substituents on the vinylic bond,molybdenum hexacarbonyl-mediated in situ carbony-lation delivered a set of indan-1-one products in high yield after only 20 min of heating.Without the addition of the tri-tert-butylphosphine releasing Fu-salt((t-Bu)_3PHBF_4),only incomplete conversions of sluggish o-styryl bromides and chlorides were realized.Internal and chemoselective palladium(O)-catalyzed Heck arylations of enamides afforded suitable starting materials for subsequent rapid ring-closing reactions.Microwave-heated intramolecular in situ carbo-nylation of these electron-rich and sterically congested olefins conveniently afforded eight functionalized 3-acylami-noindanone derivatives in a novel synthetic process.Attempted carbonylative annulation of electron-poor o-bromo-cinnamic acid derivatives furnished only the corresponding lactones via a competing hydroxycarbonylation-Michael addition reaction sequence.