539-43-5Relevant articles and documents
-
Singh, P. P.,Atreya, Kshipra
, p. 711 - 722 (1982)
-
Substituent effects in aromatic substitution of aryltriethyltin compounds by mercuric halides
Sedaghat-Herati, M. Reza,Sharifi, Taghi
, p. 39 - 44 (2007/10/02)
Second-order rate constants are reported for the reaction of some YC6H4SnEt3 compounds with mercuric halides in tetrahydrofuran, and show that the reaction is one of low selectivity.The substituent effects can be correlated only in terms of Hammett ?-constants, and the data for the meta-methoxy group are anomalous.The results indicate that the rate determining step involves reaction of a ?-complex.Activation parameters are reported, and are in accordance with the suggested mechanism.
Selectivity and reactivity in reactions of methylaryltitanium(IV) complexes with electrophiles
Puddephatt, Richard J.,Stalteri, Maria A.
, p. 1400 - 1405 (2008/10/08)
Methyl or phenyl for halogen-exchange reactions occur between [TiMe2(η-C5H5)2] or [TiPh2(η-C5H5)2] with [TiX2(η-C5H5)2], X = halogen, to give [TiXMe(η-C5H5)2] or [TiXPh(η-C5H5)2], respectively. The reactions are complicated by parallel decomposition of the methyl- or phenyltitanium complexes, which is catalyzed by [TiX2(η-C5H5)2] or [TiXR(η-C5H5)2]. In general, there is little difference in the rates of reaction of [TiMe2(η-C5H5)2] and [TiPh2(η-C5H5)2] toward the symmetrization reactions. These reagents also transfer a methyl group or phenyl group to platinum(II) or gold(III), but there are again side reactions. The complex [TiMePh(η-C5H5)2] reacts with electrophiles HCl, HOAc, HgCl2, and MeHgCl to give cleavage of both methyl- and phenyltitanium bonds with little selectivity. In cleavage of [TiMe(C6H4X)(η-C5H5) 2] there is a correlation of the selectivity for cleavage of the aryl group by electrophiles HCl or HgCl2 with the σ+ parameters of substituents X. A mechanism of reaction involving electron transfer from the complex to the electrophile followed by rapid cleavage is tentatively suggested.
