Homogeneous Ethanol CuCl 2 /TMEDA/TEMPO System Mimicking Laccase/TEMPO for the Catalytic Aerobic Oxidation of Primary Furyl, Allyl and Benzyl Alcohols
Emmanuel Dias da Silva, João Luiz Petrarca de Albuquerque, Alcindo Aparecido dos Santos, Lorena de Fontgaland Costa, José Augusto Ferreira Perez Villar, Jefferson Luiz PrincivalABSTRACT
We report herein a homogeneous ethanol CuCl 2 /TMEDA/TEMPO system for the catalytic aerobic oxidation of primary furyl, allyl, and benzyl alcohols. Under the established protocol, the reactions occur under mild conditions (25°C, open‐air atmosphere), requiring low catalyst loadings, further benefited by the use of ethanol as the renewable solvent. The optimized reaction conditions allowed the preparation of α,β‐unsaturated aldehydes in high yields (84%–99%). Additionally, a comparative study revealed that the Cu/TMEDA system performs similarly to laccase‐mediated systems (LMS), both employing TEMPO as a mediator and achieving comparable outcomes under the optimized conditions, except for propargylic alcohol 1r , which was oxidized exclusively by the LMS, and furyl alcohol 1s , which was oxidized exclusively by the Cu/TMEDA system.