Masson, EricSchlosser, Manfred2015-09-282015-09-282015-09-28201510.3998/ark.5550190.p009.019https://infoscience.epfl.ch/handle/20.500.14299/119080WOS:000358992900011The order of reactivity (X = F < Cl < Br < I) determined for the reaction of the model nucleophile pinenylpotassium with halotrimethylsilanes XSi(CH3)(3) in hexane and with halotriisopropylsilanes XSi(iC(3)H(7))(3) in tetrahydrofuran supports a single-step S(N)2(Si) mechanism over the formation of a pentavalent intermediate. However, no leaving group effect is found (X = F approximate to Cl approximate to Br approximate to I) when the condensation of pinenylpotassium with halotrimethylsilanes is accomplished in tetrahydrofuran. Under such conditions the crucial event appears to be diffusion-controlled precomplex formation followed by rapid metal halide ejection.Allylmetalssilanesnucleophilic substitutionkineticsdiffusion controltext::journal::journal article::research article