Copper-Catalysed Allylic Substitution Using 2,8,14,20-Tetrapentylresorcinarenyl-Substituted Imidazolium Salts

Murat Kaloğlu (1, 2) , Neslihan Şahin (1) , David Semeril (1) , Eric Brenner (1) , Dominique Matt (1) , İsmail Özdemir (2) , Cemal Kaya , Loic Toupet (3)

1 Institut de Chimie de Strasbourg
2 Inönü University
3 IPR - Institut de Physique de Rennes

Unsymmetrical imidazolium salts, each having one nitrogen atom (N1) substituted by a cavity-shaped TPR group (TPR = 2,8,14,20-tetrapentylresorcinaren-5-yl), were tested in situ as proligands for the copper-catalysed allylic arylation of cinnamyl bromide with arylmagnesium halides. The catalytic systems produced mixtures of linear (l) and branched (b) arylated compounds in variable proportions, with the b/l ratio being the highest (78:22) for the most crowded imidazolium salt used, namely that in which the second nitrogen atom (N2) was substituted by a mesityl group. An N-heterocyclic carbene complex obtained from one of the imidazolium salts was characterised by an X-ray diffraction study

Keywords: Allylic substitution; Calixarenes; Carbenes; Cavitands; Copper; Regioselectivity

Domains: Physics [physics]

Murat Kaloğlu, Neslihan Şahin, David Semeril, Eric Brenner, Dominique Matt, et al.. Copper-Catalysed Allylic Substitution Using 2,8,14,20-Tetrapentylresorcinarenyl-Substituted Imidazolium Salts. European Journal of Organic Chemistry, 2015, 2015 (33), pp.7310--7316. ⟨10.1002/ejoc.201501070⟩. ⟨hal-01259525⟩