May contain an organic compound metal

Organometallic chemistry and organometallic synthesis

Wen-Bo Liu, David P. Schuman, Yun-Fang Yang, Anton A. Toutov, Yong Liang, Hendrik FT Klare, Nasri Nesnas, Martin Oestreich, Donna G. Blackmond, Scott C. Virgil, Shibdas Banerjee, Richard N. Zare , Robert H. Grubbs, KN ​​Houk, and Brian M. Stoltz, “Potassium tert-Butoxide-Catalyzed Dehydrogenative C − H Silylation of Heteroaromatics: A Combined Experimental and Computational Mechanistic Study,” J. Am. Chem. Soc. 2017, 139, 6867−6879.

In this in-depth study, scientists investigated the mechanism by which potassium tert-butoxide catalyzes the dehydrogenative coupling of heteroaromatics with hydrosilanes to form heteroarylsilanes, which in turn are intermediates that can be used to form more complex molecules. For this purpose, the scientists used a ReactIR to examine the possible presence of a coordinated silane species by means of FTIR spectroscopy. Similar studies by other research groups showed that the reaction of (RO)3SiH with the corresponding KOR (R = alkyl or aryl) five-coordinate hydridosilicate [HSi (OR)4] K forms. In this study, the scientists postulated a comparable five-fold coordinated intermediate for the reaction, but this could not be confirmed by NMR studies. However, the authors report evidence of this five-coordinate species that has emerged from monitoring the silylation reaction with a ReactIR. The spectrum of this reaction showed a new peak (2056 cm-1) next to the Si-H stretch band in Et3SiH (2100 cm-1). It has been postulated that this peak is consistent with an elongated Si – H bond, as is to be expected in such pentacoordinate complexes. The authors also observed that the new peak correlates with the formation of a silylation product and postulated that the formation of five-coordinate silicate is responsible for the observed induction period in the reaction.