Intermolecular, Branch‐Selective, and Redox‐Neutral Cp*Ir^III‐Catalyzed Allylic C−H Amidation

Abstract

Herein, we report the redox-neutral, intermolecular, and highly branch-selective amidation of allylic CÀHb onds enabled by Cp*Ir III catalysis.Avariety of readily available carboxylic acids were converted into the corresponding dioxazolones and efficiently coupled with terminal and internal olefins in high yields and selectivities.M echanistic investigations support the formation of anucleophilic Ir III -allyl intermediate rather than the direct insertion of an Ir-nitrenoid species into the allylic CÀHbond.

An Update of Transition Metal-Catalyzed Decarboxylative Transformations of Cyclic Carbonates and Carbamates

“…The reactions could be carried out under mild conditions and tolerated well with different functionalities [59]. Regioselective amidation of allylic alkenes involving inert C-H activation with the use of 1,4,2-Dioxazol-5-ones as starting materials was also feasible utilizing Ir or Rh catalyst [60][61][62]. As analogs of cyclic carbamates, isatoic anhydrides have also emerged as powerful building blocks for the preparation of functionalized N-heterocycles.…”

A site-selective amination catalyst discriminates between nearly identical C–H bonds of unsymmetrical disubstituted alkenes

“…Selective allylic C–H functionalizations provide a platform for the construction of valuable building blocks from chemical feedstocks 18 , 19 , 20 , 21 , 22 . Currently, intermolecular allylic C–H amination reactions are mostly limited to alkenes with only one distinct set of allylic protons 23 , 24 , 25 , 26 , 27 , 28 , 29 , due to the lack of methods to distinguish similar allylic positions. Two important exceptions are Dauban’s work 30 31 of Rh(II)-catalyzed outer-sphere nitrene insertion preferring methylene over methyl C–H bonds and Tambar’s two-step protocol 32 where an asymmetric ene-type transformation of cis -olefins was demonstrated to distinguish between two allylic positions ( Fig.…”

Recent Development on Cp*Ir(III)‐Catalyzed C−H Bond Functionalization

“…Recently, Rovis and Glorius independently reported Ir(III)‐catalyzed intermolecular allylic C−H amidation with great branch‐selectivity. In Rovis’ work, a wide array of substituted terminal alkenes could serve as suitable substrates in this transformation (Scheme ) …”