172952-28-2Relevant academic research and scientific papers
Synthesis and reactions of tungsten oxo vinylalkylidene complexes: reactions of WCl2(O)(PX3) (X = OMe, R) precursors with 3,3-diphenylcyclopropene
Javier De La Mata,Grubbs, Robert H.
, p. 577 - 584 (2008/10/08)
Complexes of the type WCl2(O)[PX3]3 (PX3 = P(OMe)3 (1); PMePh2 (2)) were synthesized according to procedures previously described in the literature. Upon treatment with 3,3-diphenylcyclopropene, complexes 1 and 2 afforded the corresponding η2-cyclopropene complexes. Spectroscopic data of W(η2-diphenylcyclopropene)Cl2(O)[PX3] 2 (PX3 = P(OMe)3 (4); PMePh2 (5)) were consistent with an octahedral geometry in which the two mutually trans PX3 ligands and the cyclopropene ligand occupy equatorial positions cis to the apical oxo ligand. The thermal rearrangement of the η2-cyclopropene complexes leads to the dimerization product of 3,3-diphenylcyclopropene: 1,1,6,6-tetraphenyl-1,3,5-hexatriene. The presence of carbene species before the dimerization occurs has been demonstrated. Upon treatment with 2 equiv of lithium hexafluoro-tert-butoxide, complexes 4 and 5 give the vinyl alkylidene complexes W(=CHCH=CPh2)(O)[OC(CH3)(CF3)2] 2[PX3] (PX3 = P(OMe)3 (10); PMePh2 (7)). The spectroscopic data of 10 and 7 indicated a distorted trigonal bipyramid, where the oxo and alkylidene ligands are cis to each other and placed in the equatorial plane.
