Synthesis of cycloheptenones and higher homologues
A palladium-catalyzed oxidative cross-coupling of vinyl boronic acids and cyclic α-diazocarbonyl compounds enables an efficient synthesis of 1,3-diene compounds. Mechanistically, the reaction involves migratory insertion of palladium carbene as the key step.
Y. Xia, Y. Xia, Z. Liu, Y. Zhang, J. Wang, J. Org. Chem., 2014, 79, 7711-7717.
[ReBr(CO)3(thf)]2 catalyzes the reaction of a 1,3-dicarbonyl cyclic compound with an acetylene to give a medium-sized cyclic compound in excellent yield. By using isocyanide as an additive, the insertion of acetylenes into a carbon-carbon single bond occurs under mild conditions.
Y. Kuninobu, A. Kawata, K. Takai, J. Am. Chem. Soc., 2006, 128, 11368-11369.
An efficient and regioselective Yb(OTf)3-promoted palladium-catalyzed oxidative cyclization of γ-heteroalkenyl β-keto amides has been developed. Under simple aerobic condition, various six-, seven-, and eight-membered-ring N- and O-heterocycles were obtained in excellent yield.
K.-T. Yip, J.-H. Li, O.-Y. Lee, D. Yang, Org. Lett., 2005, 7, 5717-5719.