Reaction of Decamethylsilicocene with Sulfur, Selenium, and Tellurium : From a p π p π System to New Heterocycles

An η 5 ‐η 1 ‐haptotropic rearrangement in the reaction of (η 5 ‐Cp * ) 2 Si and n Bu 3 P = Se leads to intermediary formation of (η 1 ‐Cp * ) 2 Si = Se, which can be trapped with dimethylbutadiene. End products of the reaction of Cp   2 *Si with sulfur‐, selenium‐ and tellurium‐sources, however, are heterocycles: for example, reaction with n Bu 3 P = Te leads to the tritelluradisilol 1 , the first neutral tellurium‐silicon heterocycle.