Abstract
The reaction of the propargylic salt [Ph3PCH2Cî - CH]PF6 with [Pt(C2H4)(PPh3) 2] affords the η2-allenylphosphonium salt [Pt(η2-CH2î - "Cî - "CHPPh 3)(PPh3)2]PF6 via a metal-mediated propargylic rearrangement. Isomerization of the complex occurs in solution to generate the salt [Pt{η2-C(PPh3)î - "Cî - "CH2}(PPh3)2]PF 6, wherein the allene is coordinated by the internal Cî - "C bond. Computational studies indicate that the isomerization of the propargylic cation [Ph3PCH2Cî - CH]+ to the allenyl species [Ph3PCHî - "Cî - "CH 2]+ and the α-alkynyl isomer [Ph 3PCî - CCH3]+ is thermodynamically favorable. The isomeric η2-alkynylphosphonium salt [Ptη2-C(CH3)î - CPPh3(PPh 3)2]PF6 is formed from the reaction of [Ph 3PCî - CCH3]PF6 with [Pt(C 2H4)(PPh3)2] and does not isomerize to the propargylic or allenyl forms.
| Original language | English |
|---|---|
| Pages (from-to) | 4766-4774 |
| Number of pages | 9 |
| Journal | Organometallics |
| Volume | 32 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - 9 Sept 2013 |