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Higher-Valent Tellurium A Mechanistic Puzzle

The tetra- and hexa-valent states are significantly more stable for selenium and tellurium than they are for sulfur. Thus, whereas SCI4 is exceedingly unstable, decomposing above -30 °C, SeCl4 and TeC are stable under ordinary conditions. With chloride ion acceptors, both tetrachlorides form [ChCl3]+ (Ch = Se, Te) cations  [Pg.247]

Unlike its Se and S analogs, tellurium tetrachloride adds to carbon-carbon double bonds, giving tetravalent organotelluriums  [Pg.247]

The products thus obtained can then be elaborated to other organotellurium derivatives. [Pg.247]

The Stability of hexavalent tellurium was clearly demonstrated in a reaction of TeC with an aryllithium, reported by Japanese main-group chemist Kin-ya Akiba and his coworkers Tetrahedron 1997, 53, 12195-12202), which led to a disproportionation and produced a highly stable hexaaryltellurium product  [Pg.248]

We chose this reaction for discussion because, like many disproportionation reactions, the mechanism is of considerable interest. An interesting clue to the mechanism was that both TcAtjCI and TeArjCl were obtained as side products. Nucleophilic attack by ArLi on TeC produces a whole suite of products, which we may view as intermediates  [Pg.248]


See other pages where Higher-Valent Tellurium A Mechanistic Puzzle is mentioned: [Pg.247]    [Pg.247]    [Pg.249]   


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