Anodic benzylic C(sp³)–H amination: unified access to pyrrolidines and piperidines

Abstract

An electrochemical C–H amination process enables sustainable unified access to the heterocyclic classes of pyrrolidines and piperidines.

Electrochemical and Scalable Dehydrogenative C(sp3)−H Amination via Remote Hydrogen Atom Transfer in Batch and Continuous Flow

“…In conclusion, we have developedasustainable and environmentally benign protocol for an electrochemically driven,i ntramolecular direct C(sp 3 )ÀHa mination. [26] Transition-metalc atalysts and/or (super)stoichiometric oxidants were successfully replaced by "traceless" anodico xidation. The electrochemical reactionu tilizes an industrially acceptable solvent-supporting electrolyte systema nd inexpensive graphite and stainless-steel electrodes.…”

Electrocatalytic Oxidative Transformation of Organic Acids for Carbon–Heteroatom and Sulfur–Heteroatom Bond Formation

“…In the same year, Muñiz and co‐workers also reported an example of the electrochemical lactonization of aliphatic carboxylic acid in higher yield (Scheme ) …”

“…In the same year,M uÇiz and co-workers also reported an example of the electrochemical lactonization of aliphatic carboxylic acid in higheryield (Scheme 11). [20] In 2018, Neumann and co-workers reported the acetoxylation of alkylarenes catalyzed by [Co IV W 12 O 40 ] 4À in acetic acid. [13] Dehydrogenation or oxidation of alkylarenes werea lso observed in these reactions (Scheme 12).…”

Merging Photochemistry with Electrochemistry: Functional‐Group Tolerant Electrochemical Amination of C(sp3)−H Bonds

“…[5] The Hofmann-Lçffler-Freytag (HLF) reaction is ap ioneering example of such reactivity, [6,7] and numerous variations of the HLF reaction have emerged for C À Hh alogenation and nitrogen-heterocycle synthesis. [8][9][10][11] Electrochemical methods, summarized in Figure 1, have been explored as am eans to bypass the use of undesirable stoichiometric oxidants or pregeneration of N À Xc ompounds,b oth of which compromise the atom-economy and other appealing features of these methods.S everal distinct mechanistic approaches have been investigated in these electrochemical HLF-type reactions ( Figure 1A): i) stepwise ET-PT-ET to generate ab enzyl cation, which reacts with an appended nitrogen nucleophile, [12] ii)proton-coupled electron transfer (PCET) to generate an itrogen-centered radical that promotes 1,5-HAT, similar to the key C À Hactivation step in the HLF reaction, [13] and iii)bromide-mediated formation of an N-bromo intermediate that undergoes thermal NÀBr homolysis to achieve the key 1,5-HATs tep. [14,15] Each of these examples exhibits limited functional-group compatibility owing to the requirement for high anode potentials ( Figure 1B).…”