Phosphines bearing alkyne substituents: synthesis and hydrophosphination polymerization.
A synthetic route is described for a series of phosphines bearing pendant alkyne substituents, from the conversion of BrC(6)H(2)R(2)C[triple bond]CR' (R = Me, i-Pr; R' = Ph, SiMe(3)) to [(mu-Br)Cu(Et(2)N)(2)PC(6)H(2)R(2)C[triple bond]CR'](2) and subsequently to Cl(2)PC(6)H(2)R(2)C[triple bond]CR' and H(2)PC(6)H(2)R(2)C[triple bond]CR'. Lithiation and subsequent alkylation yield the secondary phosphines R(H)PC(6)H(2)(i-Pr)(2)C[triple bond]CPh (R = CH(2)i-Pr, CH(2)Ph). Intermolecular hydrophosphination-polymerization is used to prepare the polymeric species [RPC(6)H(2)(i-Pr)(2)CH=CPh](n), which can then be sulfurized to give [RP(S)C(6)H(2)(i-Pr)(2)CH=CPh](n). The polymeric products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and gel permeation chromatography. These data indicate a degree of polymerization (DP(n)) of up to 60. Discussion of the mechanism is augmented with gas-phase density functional theory calculations.
Greenberg
Sharonna
S
Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
Stephan
Douglas W
DW
D000480:Alkynes / Q000737:chemistry*; D003198:Computer Simulation; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010720:Phosphines / Q000138:chemical synthesis* / Q000737:chemistry
D000480:Alkynes; D010720:Phosphines