Facile Sc(OTf)<sub>3</sub>-Catalyzed Generation and Successive Aromatization of Isobenzofuran from <i>o</i>-Dicarbonylbenzenes
作者:Yuta Nishina、Tatsuya Kida、Tomonari Ureshino
DOI:10.1021/ol201479p
日期:2011.8.5
Isobenzofuran can be prepared from o-phthalaldehyde using hydrosilane. The formed isobenzofuran is trapped by an alkene via a Diels–Alder reaction. Further dehydration proceeds to furnish the conjugated aromatic compound. This multistep reaction was promoted by catalytic amounts of Sc(OTf)3.
By heating aryl aldehydes with catalytic amounts of a rhenium complex, ReBr(CO)(5), and N-phenylacetamide in toluene, indenone derivatives are obtained in good to excellent yields. This reaction proceeds via (1) the formation of an isobenzofuran derivative by the insertion of an aldehyde into the C-H bond of another aldehyde (C-H bond activation) and successive intramolecular nucleophilic cyclization, (2) nucleophilic addition of the formed isobenzofuran derivative to the third aldehyde, (3) isomerization, and (4) intramolecular aldol condensation.
RIGAUDY J.; PERLAT M.-C.; SIMON D.; KIM CUONG NGUYEN, BULL. SOC. CHIM. FRANCE <BSCF-AS>, 1976, NO 3-4, PART. 2, 493-500
作者:RIGAUDY J.、 PERLAT M.-C.、 SIMON D.、 KIM CUONG NGUYEN