Influence of both steric effects and te center dot center dot center dot n intramolecular nonbonded interactions on the stabilization of organotellurium compounds incorporating [2-[1-(3,5-dimethylphenyl)-2-naphthyl]-4,5-dihydro-4,4-dimethyloxazole]

Abstract

A series of novel low-valent organotellurium compounds incorporating [2-[1-(3,5-dimethylphenyl)-2-naphthyl]-4,5-dihydro-4,4-dimethyloxazole] (1) stabilized by (TeN)-N-... nonbonded interactions have been synthesized. The synthesis has been achieved by the ortholithium route. The lithium arenetellurolate 3 was obtained by direct metalation of 1 with 1.6 M of n-BuLi in hexane followed by the insertion of tellurium into the Li-C bond. Oxidation of 3 then afforded the desired ditelluride 4. The reaction of 4 with a stoichiometric amount of sulfuryl chloride yielded stable tellurenyl(II) chloride 5, whereas the addition of an excess sulfuryl chloride led to the formation of tellurium(IV) trichloride 6. The stable bromo compound 7 was obtained by the controlled bromination of 4 with bromine. No tellurium tribromide formation was observed when the ditelluride was treated with an excess of bromine. Compound 4 under-went facile reaction with a stoichiometric amount of iodine to give a stable mono iodo compound (8). The phenyltelluride derivative 9 was obtained by the treatment of lithiated product 2 with PhTeBr at low temperature. Attempts to synthesize the symmetrical telluride of the type R2Te (10) by the reaction of 2 with Te(dtc)(2) (dtc = diethyldithiocarbamate) or TeI2 were unsuccessful. All compounds were characterized by elemental analysis, multinuclear (H-1, C-13, Te-125) NMR, and mass spectrometry techniques. The presence of strong (TeN)-N-... intramolecular nonbonded interactions in all the compounds was confirmed by single-crystal X-ray crystallographic studies.