166987-47-9Relevant academic research and scientific papers
Functional ruthenium (II) allenylidene and diynyl (arene) derivatives formed by activation of a diyne via a Ru=C=C=C=C=CR2 intermediate
Péron, Daniel,Romero, Antonio,Dixneuf, Pierre H.
, p. 3319 - 3326 (2008/10/09)
The activation of the diyne HC≡CC≡CC(OSiMe3)Ph2 (II) by a variety of RuCl2(PR3)(C6-Me6) complexes 1 [PR3 = PMe3(a), PMe2Ph (b), PMePh2(c)], in the presence of the salt NaPF6, selectively leads either to [LnRu=C(OMe)CH=C=C=CR2]PF6 (3), [LnRu=C=C=C(OR)-CH=CR2]PF6 (4-6), [LnRu=C=C=C(NR′2)CH=CR2]PF6 (7), or [LnRu-C≡CC≡CC(OSiMe3)-Ph2]PF 6 (8), (LnRu = RuCl(PR3)(C6Me6)). In methanol 1a leads to the buta-1,2,3-trienylcarbene complex 3 and the 3-alkenylallenylidene derivative 4a. In ethanol and 2-propanol the complexes containing the 3-alkenylallenylidene moiety 5a-c and 6a-c are generated from 1a-c. In the presence of HNPh2 the derivatives [LnRu=C=C=C(NPh2)CH=CPh2]PF6 (7a-c) are obtained, whereas in the presence of HNiPr2, NEt3 or, ButNH2 and NaPF6 the diynyl derivatives 8a-c are selectively produced. The protonation with HBF4 of the diynyl complexes 8 in the presence of alcohol or diphenylamine is shown to displace the OSiMe3 group and generate (3-alkenylallenylidene)ruthenium derivatives 6-7*. The activation of the diyne II by complexes 1 and NaPF6 can be rationalized in terms of the formation of the electrophilic penta-1,2,3,4-tetraenylidene intermediate [(C6Me6)(PR3)Cl Ru=C=C=C=C=CPh2]+ (2), which is reactive toward weak nucleophiles.
