177695-52-2Relevant academic research and scientific papers
Synthetic and Mechanistic Studies of Electrophilic Attack by the Cations (1+) (dienyl=C6H7 or 2-MeOC6H6) on Aryltrimethyl-silanes and -stannanes
John, Glyn R.,Kane-Maguire, Leon A. P.,Odiaka, Timothy I.,Eaborn, Colin
, p. 1721 - 1728 (2007/10/02)
Synthetic and kinetic studies are reported for the reactions of the organometallic cations (1+) (I) (dienyl=C8H7) and (III) (dienyl=2-MeOC6H6) with a wide range of aryltrimethyl-silanes and -stannanes of the type XC6H4MMe3 (M=Si or Sn).Less extensive studies with related substrates (M=Pb or Ge), and with 2-trimethylsilyl-furan or -thiophen and allyltrimethylstannane, are also described.These nprovide novel routes to a variety of diene-substituted arenes and heterocycles, including the only current path to such derivatives of the less activated arenes XC6H5 (X=MeO, MeS, Me, F, Cl, Br, or H).The general rate law, rate=k, is rationalised in terms of electrophilic attack by cations (I) and (III) on the substrates XC6H4MMe3.Similarly, with 2-trimethylsilylfuran the rate=k.Linear free energy relationships reveal close similarities with related protiodemetallations.Rate data for the reactions of (1+) with XC6H4SnMe3 in CH3CN are best fitted (r=0.98) by the Yukawa-Tsuno equation, log (kx/kH) = ρ, with a ρ value of -2.7.As expected, rates vary with the nature of the metal M in the order Pb >> Sn >> Ge > Si.In general, the substrates XC6H4MMe3 are considerably more reactive towards cations (I) than are the corresponding compounds XC6H5.The only exceptions are the species 4-Me2NC6H4MMe3 (M=Si or Sn), which exhibit reactivities similar to Me2NC6H5.
