Diglyme, nickel complexes

Although the actual reaction mechanism of hydrosilation is not very clear, it is very well established that the important variables include the catalyst type and concentration, structure of the olefinic compound, reaction temperature and the solvent. used 1,4, J). Chloroplatinic acid (H2PtCl6 6 H20) is the most frequently used catalyst, usually in the form of a solution in isopropyl alcohol mixed with a polar solvent, such as diglyme or tetrahydrofuran S2). Other catalysts include rhodium, palladium, ruthenium, nickel and cobalt complexes as well as various organic peroxides, UV and y radiation. The efficiency of the catalyst used usually depends on many factors, including ligands on the platinum, the type and nature of the silane (or siloxane) and the olefinic compound used. For example in the chloroplatinic acid catalyzed hydrosilation of olefinic compounds, the reactivity is often observed to be proportional to the electron density on the alkene. Steric hindrance usually decreases the rate of... 

Miura et al. have described the nickel-catalyzed direct arylation of azoles with aryl bromides, using nickel(II) bromide or a nickel(II) bromide diglyme complex, in the presence of 1,10-phenanthroline as ligand, and lithium t-butoxide as base, in diglyme at elevated temperature. The systems were optimized for benzthiazoles, benzoxa-zoles, and 5-phenyl oxazoles benzthiazoles coupled efficiently without the addition of zinc to give 2-arylbenzthiazoles 3 (Scheme 5.1, Table 5.1). 

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