TY - JOUR
T1 - Unusual reductive coupling of alkynes and ketones
T2 - reactivity of titanacycles supported by dimethylsilylcalix[4]arene (DMSC) ligands
AU - Ozerov, Oleg V.
AU - Brock, Carolyn P.
AU - Ladipo, Folami T.
PY - 2000/11/27
Y1 - 2000/11/27
N2 - 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 RC≡CH quantitatively produced [(DMSC)Ti(η2-RC≡CH)(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(η2-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 RC≡CH 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.
AB - 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 RC≡CH quantitatively produced [(DMSC)Ti(η2-RC≡CH)(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(η2-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 RC≡CH 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.
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U2 - 10.1021/om0005349
DO - 10.1021/om0005349
M3 - Article
AN - SCOPUS:0034312006
SN - 0276-7333
VL - 19
SP - 5016
EP - 5025
JO - Organometallics
JF - Organometallics
IS - 24
ER -