Copper‐Catalyzed Oxidative Dehydrogenative C(sp³)−H Bond Amination of (Cyclo)Alkanes using NH‐Heterocycles as Amine Sources

Abstract

A copper-catalyzed oxidative C(sp 3 )-H/N-H coupling of NH-heterocycles with affordable (cyclo)alkanes was developed. This protocol involved C(sp 3 )-N bond formation via a radical pathway generated by a homolytic cleavage of di-tert-butyl peroxide and trapping of the radical(s) by copper catalysts. The reaction tolerated a series of functional groups, such as bromo, fluoro, ester, ketone, nitrile, methyl and methoxy. NH-free indoles, pyroles, pyrazoles, indazoles and benzotriazoles have been successfully N-alkylated.

Copper(II)-Photocatalyzed N–H Alkylation with Alkanes

“…Compared to the use of alkyl halides, NHPI esters, and alkyl carboxylic acids as alkylating reagents, copper peroxide catalytic systems provide a straightforward approach for the N–H alkylation using unfunctionalized C­(sp 3 )–H bonds . The proposed mechanism for these transformations usually starts with [Cu I ] and includes a sequence of tert -butoxy radical trapping, ligand exchange, alkyl radical trapping, and reductive elimination to complete the copper-catalytic cycle (Scheme ).…”

Synthesis of Diverse Functionalized Quinoxalines by Oxidative Tandem Dual C−H Amination of Tetrahydroquinoxalines with Amines

“…The copper salt initially chelates to pyridine to form a more active copper complex . Then, L n [Cu]/O 2 ‐mediated single‐electron oxidation (SEO) of the nitrogen atom of THQX 1 a leads to the radical cation 1 a′ . Due to stabilization of the SOMO by the aryl ring, 1 a′ undergoes deprotonation to yield the aryl radical 1 a′′ .…”

Copper supported on phenanthroline‐functionalized porous polymer as an active catalyst for the oxidative carbonylation of methanol

“…Copper catalyst represents an appealing alternative to traditional noble metal catalysts for carbonylation reactions. The liquid‐phase process for the oxidative carbonylation of methanol using CuCl as a commercial catalyst was first developed by Enichem Company in 1983. Nevertheless, this homogeneous process suffers from several disadvantages, such as the problem of catalyst and product separation, the corrosive effect arising from chlorine ions, and the redox reaction of copper species.…”