Synthesis of Calix[4] dithiacrown PlatinumComplexes and Their Catalytic Behavior in the Hydrosilylation of Olefins with Triethoxysilane

5, 11, 17, 23-Tetrakis-1’, 1’-dimethylethyl-25, 27-dihydroxy-26, 28-1", 7", 13"-trioxa-4", 10-dithia-tridecylcene-calix [4] arene (calix [4]dithiacrown-5 ) and its O-methylated derivate (dimethylcalix [4]dithi-acrown-5 ) were synthesized from p-tert-butylcalix [4] arene vla 1, 3-lower rim functlonalization withchloroethyltosylate, followed by rlng-closlng condensation with β,βP’-dimercaptoethyl ether in the presence of sodium ethoxide as a base in reflux ethanol under nitrogen atmosphere, rollowed hy methylation with methyl-tosylate in the presence of NaH as a base in dioxane. It was round that they can coordinate with platinous chloride and the Platinous complexes are efficient catalysts ror the kydrosilylation of olefins with triethoxysi-lane.