Destannylative acylation of 1-[(2-methoxyethoxy)methoxy]-2-(phenylsulfonyl)-2-(tributylstannyl)cyclopropane: A novel route to 3-acylfurans
作者:Manat Pohmakotr、Auntika Takampon
DOI:10.1016/0040-4039(96)00852-0
日期:1996.6
Destannylative acylation of 1-[(2-methoxyethoxy)methoxy]-2-(phenylsulfonyl)-2-(tributylstannyl)cyclopropane (1) provided dihydrofurans 5 in good yields, which upon treatment with BF3.OEt2 in CH2Cl2 led to the formation of 3-acylfurans 6 in moderate yields. The reaction was proposed to proceed via the intramolecular Prins-type reaction of the oxonium intermediate 7.
Intermolecular cross-carbonylation of aryl iodides with five-membered cyclic olefins such as dihydrofurans and cyclopentene was found to proceed by using a catalyst system of PdCl2/PPh(3) under CO (3-5 atm) in the presence of a tertiary amine. With 2,3- and 2,5-dihydrofurans, 2-aroyl-4,5-dihydro- and 3-aroyl-2,3-dihydrofurans were obtained as the predominant products, respectively, while the reaction of iodobenzene with cyclopentene gave a mixture of three regioisomers of benzoylcyclopentene. The yields of the products were observed to be markedly influenced by the amount of triphenylphosphine added.