title: N-Heterocyclic Carbene-Mediated Microfluidic Oxidative Electrosynthesis of Amides from Aldehydes.
abstract: A flow process for N-Heterocyclic Carbene (NHC)-mediated anodic oxidative amidation of aldehydes is described, employing an undivided microfluidic electrolysis cell to oxidize Breslow intermediates. After electrochemical oxidation, the reaction of the intermediate N-acylated thiazolium cation with primary amines is completed by passage through a heating cell to achieve high conversion in a single pass. The flow mixing regimen circumvented the issue of competing imine formation between the aldehyde and amine substrates, which otherwise prevented formation of the desired product. High yields (71-99%), productivities (up to 2.6 g h(-1)), and current efficiencies (65-91%) were realized for 19 amides.
authors.affiliation: Department of Chemistry, University of Southampton , Southampton, Hampshire SO17 1BJ, U.K.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Green
authors.affiliation: Department of Chemistry, University of Southampton , Southampton, Hampshire SO17 1BJ, U.K.
authors.forename: Derek
authors.initials: D
authors.lastname: Pletcher
authors.affiliation: GlaxoSmithKline, Stevenage, Herts SG1 2NY, U.K.
authors.forename: Stuart G
authors.initials: SG
authors.lastname: Leach
authors.affiliation: Department of Chemistry, University of Southampton , Southampton, Hampshire SO17 1BJ, U.K.
authors.forename: Richard C D
authors.initials: RC
authors.lastname: Brown