Cobalt induced CH bond activation and C8-arylation of caffeine with aryl bromides
摘要:
The 8-caffeinyl cobalt(I) complex (C8-caffeinyl)Co(PMe3)(4) (1) was obtained by reaction of caffeine with cobalt(I) complex CoMe(PMe3)(4) via C-H bond activation with the escape of methane. The reaction of I with arylbromide afforded cobalt(II) complex (C8-caffeinyl)Co(PMe3)(3)Br (2) and the C,C-coupling products 8-aryl caffeine (3 and 4), 8-phenyl caffeine and 8-(2'-pyridinayl)caffeine. The crystal structures of complexes 1 and 2 were determined by X-ray diffraction. (C) 2013 Elsevier B.V. All rights reserved.