Reactions into Element-Halogen Bonds

Insertion Reactions into Element-Halogen Bonds 11.6.2. Insertions of Acetylenes and Olefins... 

Insertion Reactions into Element-Halogen Bonds... 

Few group-IIA elements insert into a Pb-halogen bond to give organolead-group IIA element compounds e.g., EtjPbBr and Mg react in EtjO to yield Et Pb, Pb and EtMgBr EtjPbMgBr is an intermediate. No reaction is observed with between EtjPbCl and Mg metaP. 

The insertion of elemental tellurium into C — Li or C — Na bonds is a convenient method for the preparation of alkali metal tellurolates. Many organic lithium compounds are commercially available or can be prepared, for instance, by halogen-lithium or hydrogen-lithium exchange. The reactions of the organic lithium compounds with elemental tellurium are performed in inert organic solvents such as diethyl other, tetrahydrofuran, tetrahydrofuran/hexane, or diethyl ether/benzene at temperatures (— 196° to + 20°) compatible with the stability of the organic lithium compound. The applicability of this reaction for the synthesis of aliphatic, aromatic, and heteroaromatic lithium tellurolates is documented in Table 1 (p. 155). 

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