Acetamido-TEMPO as organocatalyst and mediator in the oxidation of fluorinated and non-fluorinated alcohols

POLITANO, FABRIZIO; BRYDON, WILLIAM P.; SCHROEDER, CHELSEA M.; LEÓN SANDOVAL, ARTURO; LEADBEATER, NICHOLAS E.

Reston VA

Conferencia; 26th Annual Green Chemistry & Engineering Conference; 2022

American Chemical Society

Oxoammonium salts have been broadly used as oxidants in a variety of transformations ranging from simple alcohol oxidations to more complex reactions such as oxidative amidations and esterifications. Despite its efficiency and simplicity to use, super-stoichiometric amounts of the salt are needed. A more sustainable alternative is to employ its radical precursor as a pro-oxidant and a cheaper, greener electron source as a terminal oxidant.A simple and robust, metal-free route for the oxidation of trifluoromethyl alcohols and secondary alcohols to ketones is described. The methodology employs sodium persulfate as a primary oxidant and a catalytic quantity of 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxyl (acetamido-TEMPO, ACT), and it is applicable to fluorinated and non-fluorinated alcohols. Going one step beyond, the recent advances in electrochemical oxidations of secondary alcohols by using ACT as mediator are presented. In this way the oxidation of alcohols to ketones can be reached in a greener fashion substituting a chemical terminal oxidant by just an electrons current.