American Chemical Society, Journal of the American Chemical Society, 2(137), p. 588-591, 2015
DOI: 10.1021/ja5113468
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This paper is dedicated to Yves Chauvin. ; International audience ; By grafting TaMe5 on Aerosil(700), a stable, well-defined, silica-supported tetramethyl tantalum(V) complex, [( SiO)TaMe4], is obtained on the silica surface. After thermal treatment at 150 degrees C, the complex is transformed into two surface tantalum methylidenes, [( SiO)(2)Ta(-CH2)Me] and [( SiO)Ta(-CH2)Me-2], which are active in alkane metathesis and comparable to the previously reported [( SiO)(2)TaHx]. Here we present the first experimental study to isolate and identify a surface tantalum carbene as the intermediate in alkane metathesis. A systematic experimental study reveals a new reasonable pathway for this reaction.