Nucleophilic Isomerization of Epoxides by Pincer-Rhodium Catalysts: Activity Increase and Mechanistic Insights
Herein, we present the efficient isomerization of epoxides into methyl ketones with a novel pincer-rhodium complex under very mild conditions. The catalyst system has an excellent functional group tolerance and a wide array of epoxides was tested. The corresponding methyl ketones were obtained in very high yields with excellent chemo- and regioselectivity. In addition, we investigated mechanistic details like the isomerization of the catalyst, and we obtained evidence that the catalytic cycle follows a β-hydride elimination-reductive elimination pathway after the nucleophilic ring opening of the epoxide.
Regio- and chemoselective rearrangement of terminal epoxides into methyl alkyl and aryl ketones
The development of the highly active pincer-type rhodium catalyst 2 for the nucleophilic Meinwald rearrangement of functionalised terminal epoxides into methyl ketones under mild conditions is presented. An excellent regio- and chemoselectivity is obtained for the first time for aryl oxiranes.
Tian, Yingying,Jürgens, Eva,Kunz, Doris
p. 11340 - 11343
(2018/10/31)
An unexpected oxidation of unactivated methylene C-H using DIB/TBHP protocol
An in situ generated hypervalent iodine species, bis(tert-butylperoxy) iodobenzene, was used as a peroxy radical source for the oxidation of unreactive, remote, and isolated alkyl (cyclic or aliphatic) esters and amides to the corresponding keto compounds under very mild conditions.