Silicon halides olefins

NH, NH-, -CN), silicon and olefinic double bonds are more polymerizable while those containing oxygen (e.g. -C=0,-0-,-0H), chlorine, aliphatic hydrocarbon and cyclic hydrocarbons tend to decompose. Brown (13) reported in his studies of a series of vinyl halides that the dihaloethylenes polymerize more rapidly than the corresponding monohalides and that chlorides and bromides polymerize more rapidly than the fluorides. Kobayashi, et. al. (IJ) found that the additons of certain halo-genated compounds to hydrocarbon monomer streams often dramatically increases the polymerization rate. Thus, these halogenated compounds may be considered to act as gas phase catalysts for the plasma polymerization of hydrocarbons. 

The reaction of thiyl radicals with silicon hydrides (Reaction 3.18) is the key step of the so called polarity-reversal catalysis in the radical-chain reduction of alkyl halides as well as in the hydrosilylation of olefins using silane-thiol couple (see Sections 4.5 and 5.1) [33]. The reaction is strongly endothermic and reversible (Reaction —3.18). 

Various activated olefins can also be employed instead of organic halide for the formation of a carbon-silicon bond. Thus, cathodic reduction of a,j -unsaturated esters, nitriles... 

Recently, it was found that organometallic compounds, such as silicon (equation tin (eqnation 8), antimony (eqnation 9), and lead (eqnation 10), instead of organic halides, react with olefins to produce the same products as obtained by the MH reaction. 

In contrast to the rare occurrence of the oxidative addition of C-C bonds, the oxidative addition of the nonpolar bonds between two main group atoms, such as boron and silicon, can be facile. The oxidative addition of Si-Si bonds in disilanes and the B-B bond in diborane(4) reagents is likely to be a step in a variety of catalytic reactions, including the additions of disilanes, - diborane(4) reagents, and silaboranes - across olefins and alkynes, the silylation and borylation of arene C-H bonds, - - the borylation of alkane C-H bonds, and the conversion of aryl halides to arylsilanes and arylbo-ronate esters. " ... 

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