Rhenium-catalyzed synthesis of indenones by novel dehydrative trimerization of aryl aldehydes via C-H bond activation.
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.
Division of Chemistry and Biochemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Kita-ku, Okayama 700-8530, Japan. kuninobu@cc.okayama-u.ac.jp
Yoichiro
Y
Kuninobu
Takashi
T
Matsuki
Kazuhiko
K
Takai
D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D007192:Indenes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D012211:Rhenium / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D007192:Indenes; D012211:Rhenium