Tellurophene reaction with osmium complexes

Reaction of tellurophene with osmium or ruthenium clusters [M3(CO)io(MeCN)2] (Equation 9) is accompanied by cleavage of a Te-C bond resulting in the formation of the complexes [Os3(CO)ioC4H4Te] <1990CC1568> and [Ru3(CO)ioC4H4Te] <1991JOM63>. 

Although C-S bond cleavage reactions between thiophenes and osmium clusters have not been observed, selenophene and tellurophene undergo ring opening reactions with [Os3(CO)io(NCMe)2] to give complexes 28a and 28b (Scheme T). " It is likely that the sulfur-extrusion reactions of iron and ruthenium carbonyl clusters with thiophenes proceed via ring-opened intermediates of this type. 

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