RESUMEN
Metallafuran complexes with a fused five-membered phosphonium ring were synthesized from reactions between terminal ynones HC≡C(C=O)R and cis-[Ru/Os(dppm)2 Cl2 ] (dppm=1,1-bis(diphenylphosphino)methane). A metal-vinylidene-involving pathway was found to be an energetically feasible formation mechanism for these complexes. These phosphonium-containing metallafurans, like many phosphonium-functionalized drugs, have the ability to induce mitochondrial dysfunction. They also exhibit stronger cytotoxicity against several human cancer cell lines in comparison with their metal precursors and the classic anticancer drug cisplatin. Overall, this work provides structural and mechanistic insights for the rational design of functional metallacycles via activation of alkynes by RuII and OsII centers.
RESUMEN
Two types of unexpected quinolizinium complexes were obtained from the reactions between pyridine-functionalized propargylic alcohol HC[triple bond, length as m-dash]CC(OH)(Ph)(CH2(2-py)) (L1) and cis-[M(L^L)2Cl2] (M = Ru, Os; L^L = 1,1-bis(diphenylphosphino)methane (dppm), 2,2'-bipyridine (bpy)). Their molecular structures revealed that L1 can be activated by Ru and Os via the conventional "vinylidene-involving" or unconventional "non-vinylidene-involving" pathways.
RESUMEN
Reactions between pyridine-functionalized alkynes and an Fe(ii) precursor supported by 2,5,8-trithia[9](2,9)-1,10-phenanthrolinophane afforded the first Fe(ii)-indolizine and -indolizinone complexes. Structural analysis and theoretical calculations revealed the existence of unconventional "non-vinylidene" pathways and challenged the generality of vinylidene intermediacy in Fe(ii)-induced alkyne transformations.
RESUMEN
The two series of ruthenium-indolizinone complexes prepared by Ru-mediated cyclization of pyridine-tethered alkynes represent the first examples of metalated indolizinone complexes. Joint experimental-theoretical investigation suggests an unconventional 5-endo-dig cyclization pathway as their formation mechanism. They also exhibit moderate cytotoxicity against several human cancer cell lines.