[W(CO)5]-catalyzed endo- or exo-cycloisomerization reactions of 1,1-disubstituted 4-pentyn-1-ols: experimental and theoretical studies.
The [W(CO)5]-catalyzed cycloisomerization reaction of 1,1-disubstituted 4-pentyn-1-ol derivatives has been studied from both, an experimental and theoretical point of view. Three different catalytic systems have been evaluated {preformed [(thf)W(CO)5], [W(CO)6]/excess Et3N, and [W(CO)6]/2 mol % Et3N]. We have found that the reaction proceeds to give the formal endo- or exo-cycloisomerization products depending on the amount of Et3N used and on the substitution along the alkyl chain of the starting alkynol. The theoretical study allowed us to find the mechanisms of the reactions which explain the formation of the formal endo- or exo-cycloisomerization products.
Barluenga
José
J
Instituto Universitario de Química Organometálica, Enrique Moles, Unidad Asociada al CSIC, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain. barluenga@uniovi.es
Diéguez
Alejandro
A
Rodríguez
Félix
F
Fañanás
Francisco J
FJ
Sordo
Tomás
T
Campomanes
Pablo
P
D002384:Catalysis; D003500:Cyclization; D004563:Electrochemistry; D009682:Magnetic Resonance Spectroscopy; D008962:Models, Theoretical; D013056:Spectrophotometry, Ultraviolet; D017973:Tungsten Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
D017973:Tungsten Compounds