title: Microwave-enhanced carbonylative generation of indanones and 3-acylaminoindanones.
abstract: The development of microwave-accelerated protocols for palladium(0)-catalyzed carbonylative cyclization of unsaturated aryl bromides and chlorides is described. By employing o-bromostyryl derivatives lacking substituents on the vinylic bond, molybdenum hexacarbonyl-mediated in situ carbonylation 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)(3)PHBF(4)), only incomplete conversions of sluggish o-styryl bromides and chlorides were realized. Internal and chemoselective palladium(0)-catalyzed Heck arylations of enamides afforded suitable starting materials for subsequent rapid ring-closing reactions. Microwave-heated intramolecular in situ carbonylation of these electron-rich and sterically congested olefins conveniently afforded eight functionalized 3-acylaminoindanone derivatives in a novel synthetic process. Attempted carbonylative annulation of electron-poor o-bromocinnamic acid derivatives furnished only the corresponding lactones via a competing hydroxycarbonylation-Michael addition reaction sequence.
authors.affiliation: Organic Pharmaceutical Chemistry, Department of Medicinal Chemistry, Uppsala University, BMC, Box-574, SE-751 23 Uppsala, Sweden.
authors.forename: Xiongyu
authors.initials: X
authors.lastname: Wu
authors.forename: Peter
authors.initials: P
authors.lastname: Nilsson
authors.forename: Mats
authors.initials: M
authors.lastname: Larhed