Polychlorinated Amides and Lactones via Electrochemically Mediated Copper-Catalyzed Atom Transfer Radical Addition

Area of Science:

• Organic Synthesis
• Electrochemistry
• Organometallic Chemistry

Background:

• Carbon-carbon bond formation is crucial in organic synthesis.
• Electrochemically mediated atom transfer radical addition (eATRA) is an emerging sustainable strategy.
• Copper catalysis offers efficient pathways for radical reactions.

Purpose of the Study:

• To explore copper(II)-catalyzed eATRA using α-haloamides and functionalized alkenes.
• To investigate the formation of novel polychlorinated amides and subsequent lactones.
• To elucidate the mechanism involving a unique O-bound copper(II) amidate species.

Main Methods:

• Utilized robust organocopper(II) complexes for catalysis.
• Employed electrochemistry for generating reactive copper intermediates.
• Characterized reaction products and intermediates using cyclic voltammetry and UV-vis spectroelectrochemistry.

Main Results:

• Efficient eATRA catalysis was achieved with various functionalized alkenes, yielding unique polychlorinated amides.
• Subsequent intramolecular cyclization of addition products formed five-membered lactones, controlled by alkene substitution.
• Identified and characterized a key O-bound copper(II) amidate species, [CuII(Me6tren)(OR)]+, responsible for radical generation.

Conclusions:

• Demonstrated the versatility and efficiency of copper-catalyzed eATRA under mild electrochemical conditions.
• Showcased the utility of readily available α-haloamides and alkenes for synthesizing complex amides and lactones.
• Provided mechanistic insights into the copper-mediated radical generation and eATRA process.