139565-68-7Relevant academic research and scientific papers
Ruthenium-catalyzed Arbuzov rearrangement of (allyloxy)phosphines: Isolation and X-ray structure analysis of an intermediate leading to mechanistic conclusions
Ji, Hong-Li,Nelson, John H.,De Cian, Andre,Fischer, Jean
, p. 1618 - 1626 (2008/10/08)
The [CpRu(CH3CN)3]PF6-catalyzed classical Arbuzov rearrangement of (allyloxy)phosphines PhnP-(OC3H5)3-n (n = 0-2) at room temperature in neat (allyloxy)phosphine proceeds to completion in a short time period and gives only the classical Arbuzov rearrangement products, PhnP(O)(C3H5)(OC3H5) 2-n (n = 0-2). The reaction mechanism was studied in acetonitrile solution by 31P{1H} NMR spectroscopy and supported by isolation and characterization of intermediates and final products. In addition to the classical Arbuzov product, with Ph2P(OC3H5), the mono-chelation product [CpRu(CH3CN){η3-Ph2P(OC3H 5)]PF6 (6) was isolated and characterized; with PhP(OC3H5)2, the bis-chelation products [CpRu{η5-PhP(OC3H52}]PF 6 (5a,b) were isolated and characterized; with P(OC3H5)3, the intermediate phosphite complex [CpRu{η5-P(OC3H5)3}]PF 6 (2), the final product of dealkylation [CpRu{η5-P(O)(OC3H5)2}] (4), the alkylation product [CpRu(η3-C3H5)(CH3CN) 2][PF6]2 (1), and the hydrolysis product [CpRu{η5-P(OH)(OC3H5)2}]PF 6 (3) have been isolated and characterized by elemental analysis, infrared spectroscopy, and 1H, 13C{1H}, and 31P{1H} NMR spectroscopy. The structure of 2 was confirmed by X-ray crystallography. It crystallizes in the monoclinic space group P21/n in a unit cell of dimensions a = 7.603 (5) A?, b = 20.507 (3) A?, c = 12.054 (2) A?, β = 97.45 (2)°, and ρcalcd = 1.829 g cm-3 with Z = 4. Refinement converged to R = 0.041 and 1892 independent observed (I/σ(I) ≥ 3.0) reflections. The two coordinated alkene moieties are inequivalent having different dihedral angles between the planes of the C5H5 rings and the C-C axes (4.8, 36.10°) and slightly different average Ru-C bond distances of 2.213 (8) and 2.239 (9) A?. The P-OH and P=O complexes, 3 and 4, are interconvertible via simple acid-base reactions.
