Tellurium complexes alkylations

Many of these complexes were purified by chromatography. The pure compounds are sensitive towards atmospheric oxygen. The bare tellurium atoms in these complexes can be protonated alkylated with methyl iodide, methyl lithium triethyloxonium tetrafluoroborate or methyl trifluoromethylsulfonate and reacted with diazoalkanes to produce complexes with coordinated telluroformaldehyde or telluroacetone. The anion [O = MoTeJ combined with dimethyl acetylenedicarboxylate to produce a tellurolate-containing molybdenum compound ... 

Aryl tellurium trichlorides and N-, S-, or 0-donor ligands form 1 1 complexes when the components are combined in an organic solvent. Several complexes with a 1 2 stoichiometry and one complex with a 1 4 stoichiometry were also prepared. The few complexes of alkyl tellurium trihalides that are reported in the literature all have 1 1 stoichiometry The following organic compounds served as ligands. ... 

Alkyl phenyl telluriums and diaryl telluriums react with Grignard reagents in THF or diethyl ether in the presence of catalytic amounts of nickel- or cobalt-phosphane complexes. Tellurium is precipitated. The organic groups combine to form in most cases all three possible coupling products in ratios determined by reaction conditions . The reaction of ( Z,)-phenylethenyl phenyl tellurium and phenyl magnesium bromide formed almost exclusively ( Zj-stilbene in quantitative yield. ( ZJ-Ethoxycarbonylethenyl phenyl tellurium and phenyl magnesium bromide reacted differently ( Fj-ethoxycarbonyl-(phenyl)-ethene and diphenyl tellurium were produced. Tellurium was not formed. ... 

The following metal compounds are used for the preparation of the catalysts oxides, metal carbonyls, halides, alkyl and allyl complexes, as well as molybdenum, tungsten, and rhenium sulfides. Oxides of iridium, osmium, ruthenium, rhodium, niobium, tantalum, lanthanum, tellurium, and tin are effective promoters, although their catalytic activity is considerably lower. Oxides of aluminum, silicon, titanium, manganese, zirconium as well as silicates and phosphates of these elements are utilized as supports. Also, mixtures of oxides are used. The best supports are those of alumina oxide and silica. 

When treated with half of an equivalent of Bt2, 227 and 228 gave dicationic disulfide 239 and diselenide 240, respectively. Similar to sulfur complex 231, selenone 228 could also be alkylated by refluxing the compound in iodometh-ane. Unlike NHC-Sel2 237, a dimeric complex (241) was obtained when an NHC-derived tellurone with small A -substituents C IEt-Te) was treated with I2. Each tellurium atom in 241 was in a square planar coordination environment, and the Te2l2 core was rhombohedral, with two short Te-I bonds of 2.989 and 2.897 A and one long Te-I interaction of 3.564 A for each Te atom. ... 

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