Formation of a cyclobutylidene ring: intramolecular [2 + 2] cycloaddition of allyl and vinylidene C=C bonds under mild conditions.
Intramolecular [2 + 2] cycloaddition of two C=C bonds in vinylidene complexes [Ru(eta5-C9H7){=C=C(R)H}(PPh3){kappa1-(P)-PPh2(C3H5)][BF4] affords cyclobutylidene complexes [Ru(eta5-C9H7){kappa2-(P,C)-(=CC(R)HCH2CHCH2PPh2)}(PPh3)][BF4], which can be also obtained by reaction of terminal alkynes with [Ru(eta5-C9H7)(PPh3){kappa3-(P,C,C)-PPh2(C3H5)}][PF6]. The reaction proceeds under mild conditions via vinylidene complexes, and the activation parameters were determined by kinetic studies.
Alvarez
Patricia
P
Departamento de Química Orgánica e Inorgánica, Instituto de Química Organometálica Enrique Moles (Unidad Asociada al C.S.I.C.), Facultad de Química, Universidad de Oviedo, 33006 Oviedo, Spain.
Lastra
Elena
E
Gimeno
José
J
Bassetti
Mauro
M
Falvello
Larry R
LR