title: THF: an efficient electron donor in continuous flow radical cyclization photocatalyzed by graphitic carbon nitride.
abstract: Mesoporous graphitic carbon nitride (mpg-C3 N4 ) was found to be an efficient heterogeneous photocatalyst for the metal-free radical cyclization of 2-bromo-1,3-dicarbonyl compounds. Reactions leading to functionalized cyclopentanes proceed under mild conditions and can be conducted in a continuous flow photoreactor. Compared to the batch reaction, the use of a continuous flow reactor resulted in a significant reduction in reaction time (complete conversion of 0.04 mmol of substrate in a batch was achieved after 4 h, whereas in a flow reactor the same amount of substrate was fully converted into a product within 40 min). Mechanistic studies of the reaction showed that THF plays not only the role of solvent, but is also a crucial hydrogen and electron donor.
authors.affiliation: Institute of Chemistry, Technical University Berlin, Strasse des 17. Juni 135, 10623 Berlin (Germany), Fax: +49 30 314 29745.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Woźnica
authors.forename: Nicolas
authors.initials: N
authors.lastname: Chaoui
authors.forename: Soraya
authors.initials: S
authors.lastname: Taabache
authors.forename: Siegfried
authors.initials: S
authors.lastname: Blechert
keywords: carbon nitride; continuous flow; heterogeneous catalysis; photocatalysis; radical reactions