Unusual reductive coupling of alkynes and ketones: Reactivity of titanacycles supported by dimethylsilylcalix[4]arene (DMSC) ligands uri icon

abstract

  • Reaction of [(DMSC)Ti{1,2,4-(Me3Si)3C6H3}] (1) with 1 equiv of bipyridine (bpy) or 4,4-dimethyl-2,2-dipyridyl (dmbpy) and a slight excess of RCCH quantitatively produced [(DMSC)Ti(2-RCCH)(L2)] (L2 = bpy or dmbpy) (5-16). (DMSC)TiPh2 (17) reacted with 2 equiv of bpy or dmbpy to give (DMSC)Ti(bpy)2 (18) and (DMSC)Ti(dmbpy)2 (19), respectively. Both 1H and 13C NMR data, as well as X-ray crystallography in the case of [(DMSC)Ti(2-HC=CBut)(bpy)] (7), support exo-orientation of the alkyne's non-H substituent in 5-16. Reaction of [(DMSC)Ti{1,2,4-(Me3Si)3C6H3}] (1) with a mixture of RCCH and R2CO did not give the expected 5-oxa-1-titana-2-cyclopentene products but instead produced 2,7-dioxa-1-titana-4-cycloheptenes (20-25). The latter result may be understood in terms of the unique directing influence of the DMSC ligand. 2000 American Chemical Society.

published proceedings

  • ORGANOMETALLICS

author list (cited authors)

  • Ozerov, O. V., Brock, C. P., Carr, S. D., & Ladipo, F. T.

citation count

  • 18

complete list of authors

  • Ozerov, OV||Brock, CP||Carr, SD||Ladipo, FT

publication date

  • November 2000