Access to Indenones by Rhodium(III)-Catalyzed C–H Annulation of Arylnitrones with Internal Alkynes
作者:Zisong Qi、Mei Wang、Xingwei Li
DOI:10.1021/ol4025309
日期:2013.11
Under redox-neutral conditions, rhodium(III)-catalyzed C–H annulation of N-tert-butyl-α-arylnitrones with internal alkynes has been realized for the synthesis of indenones under mild conditions. This reaction proceeded in moderate to high yields and with good functional group tolerance.
involve chlororhodation to the alkynes by the intermediary arylchlororhodium(III) species generated in situ followed by reductive elimination of the products, which are suggested by the results of some control experiments. In contrast to the reaction with terminal alkynes, that with some internal ones proceeds without decarbonylation to produce 2,3-disubstituted-1-indenones as the predominant products.
A palladium‐catalyzed ligand‐free carbonylation reaction has been developed for the synthesis of indenones. Under CO atmosphere, this cascade reaction proceeded smoothly to provide the desired indenones in moderate to excellent yields with good functional‐group compatibility. The mechanistic investigations suggested the in situ formation of palladium nanoparticles and this transformation was driven
Rhodium-Catalyzed Annulation Reactions of 2-Cyanophenylboronic Acid with Alkynes and Strained Alkenes
作者:Tomoya Miura、Masahiro Murakami
DOI:10.1021/ol051249u
日期:2005.7.1
A new [3 + 2] annulation reaction was developed in which 2-cyanophenylboronic acid reacted as a three-carbon component with alkynes or alkenes to afford substituted indenones or indanones. The use of an alkynoate even produced benzotropone, a formal [3 + 2 + 2] adduct. The cyclic skeletons were constructed by intramolecular nucleophilic addition of an intermediate organorhodium(I) species to a cyano group.