title: Electron-transfer-initiated benzoin- and Stetter-like reactions in packed-bed reactors for process intensification.
abstract: A convenient heterogeneous continuous-flow procedure for the polarity reversal of aromatic α-diketones is presented. Propaedeutic batch experiments have been initially performed to select the optimal supported base capable to initiate the two electron-transfer process from the carbamoyl anion of theN,N-dimethylformamide (DMF) solvent to the α-diketone and generate the corresponding enediolate active species. After having identified the 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine on polystyrene (PS-BEMP) as the suitable base, packed-bed microreactors (pressure-resistant stainless-steel columns) have been fabricated and operated to accomplish the chemoselective synthesis of aroylated α-hydroxy ketones and 2-benzoyl-1,4-diones (benzoin- and Stetter-like products, respectively) with a good level of efficiency and with a long-term stability of the packing material (up to five days).
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Zaghi
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Ragno
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Di Carmine
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Carmela
authors.initials: C
authors.lastname: De Risi
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Olga
authors.initials: O
authors.lastname: Bortolini
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Giovannini
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Fantin
authors.affiliation: Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Ferrara, Via Fossato di Mortara 17, I-44121 Ferrara, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Massi
keywords: C–C coupling; continuos-flow; diketone; electron-transfer; umpolung