The cathodic reduction of dicationic imidazolium bromides, whose spacer is either an aliphatic chain or a xylyl group, leads to the formation of the corresponding N-heterocyclic carbenes (NHCs), which were isolated as the corresponding thiones, after reaction with elemental sulfur. The behaviour of the dications was compared with the corresponding monocations. The behaviour of dicarbenes depends on the nature of the spacer. This study evidenced that dicarbenes deriving from xylyl dications are less stable than the corresponding aliphatic ones (giving lower yields in thiones), due to a debenzylation reaction. On the other hand, the yields in thiones starting from aliphatic dications are higher than the corresponding monocations, suggesting a cooperative reduction at the electrode of the two imidazolium moieties. The cathodic process was confirmed using the co-electrogenerated hydrogen to reduce 2,2,2- trifluoroacetophenone to the corresponding alcohol.

Daniele Rocco, I.C. (2019). Cathodic Behaviour of Dicationic Imidazolium Bromides: The Role of the Spacer. CHEMELECTROCHEM, 6, 4275-4283 [10.1002/celc.201900099].

Cathodic Behaviour of Dicationic Imidazolium Bromides: The Role of the Spacer

Francesca D'Anna;Carla Rizzo;
2019-01-01

Abstract

The cathodic reduction of dicationic imidazolium bromides, whose spacer is either an aliphatic chain or a xylyl group, leads to the formation of the corresponding N-heterocyclic carbenes (NHCs), which were isolated as the corresponding thiones, after reaction with elemental sulfur. The behaviour of the dications was compared with the corresponding monocations. The behaviour of dicarbenes depends on the nature of the spacer. This study evidenced that dicarbenes deriving from xylyl dications are less stable than the corresponding aliphatic ones (giving lower yields in thiones), due to a debenzylation reaction. On the other hand, the yields in thiones starting from aliphatic dications are higher than the corresponding monocations, suggesting a cooperative reduction at the electrode of the two imidazolium moieties. The cathodic process was confirmed using the co-electrogenerated hydrogen to reduce 2,2,2- trifluoroacetophenone to the corresponding alcohol.
2019
Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie
Settore CHIM/06 - Chimica Organica
Daniele Rocco, I.C. (2019). Cathodic Behaviour of Dicationic Imidazolium Bromides: The Role of the Spacer. CHEMELECTROCHEM, 6, 4275-4283 [10.1002/celc.201900099].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/374095
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