Dichalcogenides reaction with

Recently, however, Tokitoh and co-workers " °° reported a versatile reactivity of Tbt-substituted plumbylenes 182a-d, that is, insertion reactions with alkyl halides, diphenyl dichalcogenides, bromine abstraction from carbon tetrabro-mide, and sulfurization with elemental sulfur as shown in Scheme 14.83. 

The tendency of intermediate heterocyclic ditellurides to eliminate one of the tellurium atoms thus contracting the size of the ring is illustrated by the course of the oxidative cyclization of the dilithio dichalcogenides 78 (84JHC413). Whereas in the case of the diselenolate 78 (M = Se) the expected heterocyclic diselenide 79a is formed, albeit in low yield, the analogous reaction with the ditellurolate 78 (M = Te) results in an extrusion of elemental tellurium affording dibenzotellurophene 79b. 

The disproportionation reactions with graphite of oxidants that are also strong Tewis acids parallel the intercalation of molecular species into the layered dichalcogenides, which are reductants and Tewis bases (see Section 3.2.1). 

Tl5-C5(CH3)5]2Yb.(C4H80) reaction with fluoroalkenes 10.3.2.1.1 reaction with organic peroxides and other dichalcogenides 10.3.2.2.1... 

Scheme 15.55 also indicates the rate constants for the Sh2 reaction of alkyl radicals with diphenyl dichalcogenides. The rate constants for the Sh2 reaction with (PhSe)2 are larger than those with (PhS)2 by a factor of ca. 160 [135]. The carbon-radical-capturing ability of (PhTe)2 (Scheme 15.57) is also excellent, a factor of 4 better than that of (PhSe)2. 

The thermolysis of 2,2-dimethyl-2,3-dihydrobenzo[6]selenophen oxide (215) proceeded by sy/i-elimination of selenoxide and intramolecular addition of the intermediate benzeneselenenic acid, Cleavage of 5-triselenan by its reaction with bromine offers a preparative pathway to bis-(bromomethyl) selenide. A series of naphthalene and tetracene dichalcogenides (216 X, Y = S, Se, or Te) were... 

The reactions of carbon dichalcogenides other than C02 with Ni° have also been studied quite intensively.2460,2461 Inter alia, Ni polymeric complexes with metallic properties have been prepared using CS2 as the starting material.2462 Some further impetus was given by the observation that CS2 can mimic the binding of CO to the CODH enzyme active site, although CS2 itself does not undergo oxidation/reduction and does not appear to bind to center C (the site of CO oxidation and C02 reduction).2463... 

The strong interaction of the 13 /I" redox system with the metal dichalcogenide materials was recently exploited (31) to bring about the visible light-driven process representeiTby equation (10). In 50% by weight H2SO4 the reaction as written... 

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