A simple and efficient palladium-catalyzed intramolecular carbonylativesynthesis of isocoumarins and phthalides from the easily available starting materials by employing phenylformate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.
Palladium-catalyzed aryl halide carbonylation–intramolecular O-enolate acylation: efficient isocoumarin synthesis, including the synthesis of thunberginol A
作者:Andrew C. Tadd、Mark R. Fielding、Michael C. Willis
DOI:10.1039/b917839b
日期:——
Exposure of a series of α-(o-haloaryl)-substituted ketones to palladium-catalyzed carbonylation conditions leads to the formation of the corresponding isocoumarins. Balloon pressure of CO is sufficient to achieve high yielding reactions, and both cyclic and acyclic ketones are efficient substrates. The utility of the method is illustrated by a short synthesis of the natural product thunberginol A.
Reactions of o-iodohalobenzenes with carbanions of aromatic ketones. Synthesis of 1-aryl-2-(o-halophenyl)ethanones
作者:María T. Baumgartner、Liliana B. Jiménez、Adriana B. Pierini、Roberto A. Rossi
DOI:10.1039/b201692c
日期:2002.5.22
retention of one halogen. The monosubstituted dehalogenated compounds are formed in low overall yields in the reactions of o-diiodobenzene with the carbanions of 1-(2-naphthyl)ethanone and of acetophenone and in the reaction of o-bromoiodobenzene with the carbanion of propiophenone. The reactions can be performed in the dark, with usually increased yields of substitution under irradiation, as well as under
Herein, we report that palladium catalyzes the borylative cyclization of α-(2-bromoaryl) ketones to afford 1,2-benzoxaborinines. The developed system is compatible with a variety of functionalities (Me, t-Bu, OMe, NMe2, F, Cl, CN, CF3, CO2Me, and heteroaryl groups) and is applicable to the synthesis of B–O-containing tri- and tetracyclic fused-ring compounds.