Vinylzirconium intermediates

When telluroalkynes 105 are submitted to the hydrozirconation, only the vinylzirconium intermediates 106 are formed.179,181 These are captured with organotellurium halides to give bistelluroketene acetals 107 (Scheme 64).179... 

Similarly, hydrozirconation of stannyl acetylenes 108 followed by treatment of the intermediate vinylzirconium species 109 with -butyltellurium bromide and then with sodium borohydride gives tintelluroketene acetals 110 (Scheme 65).182... 

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