Intramolecularly Coordinated Low-Valent Organotellurium Complexes Derived from 1-(Dimethylamino)naphthalene

Abstract

A series of low-valent intramolecularly coordinated organotellurium compounds incorporating the 8-(dimethylamino)-1-naphthyl group has been synthesized by the organolithium route. Insertion of elemental tellurium into the Li−C bond of RLi (2) affords the tellurolate RTeLi (3) (R = 8-(dimethylamino)-1-naphthyl). Oxidative workup of 3 gives dark red ditelluride 4 in moderate yield. Reaction of 2 with “PhTeBr” afforded telluride 5. Interestingly, the reaction of 2 with TeI2 afforded the stable tellurenyl iodide 6 instead of the expected telluride R2Te. Controlled bromination of ditelluride with bromine in chloroform gave stable tellurenyl bromide 7 whereas bromination with excess bromine leads to the isolation of tellurium(IV) tribromide 8. Ditelluride 4 was found to be inert to the reactions with diazomethane and reducing agents like NaBH4, NaH, and LiAlH4. The compounds were characterized by elemental analysis, NMR (1H, 13C, 125Te), and mass spectroscopic techniques. For three of these compounds R2Te2 (4),...