789-25-3Relevant articles and documents
Biernbaum,Mosher
, p. 6221 (1971)
The Role of (tBuPOCOP)Ir(I) and Iridium(III) Pincer Complexes in the Catalytic Hydrogenolysis of Silyl Triflates into Hydrosilanes
Berthet, Jean-Claude,Cantat, Thibault,Durin, Gabriel,Nicolas, Emmanuel,Thuéry, Pierre
supporting information, (2021/12/09)
Hydrosilanes are convenient reductants for a large variety of organic substrates, but they are produced via energy-intensive processes. These limitations call for the development of general catalytic processes able to transform Si-O into Si-H bonds. We report here the catalytic hydrogenolysis of R3SiOTf (R = Me, Et, and Ph) species in the presence of a base (e.g., NEt3), by the hydride complexes [(tBuPOCOP)IrH(X)] (X = H and OTf; (tBuPOCOP = [C6H3-2,6(OPtBu)2]. Syntheses and crystal structures of new iridium(I) and iridium(III) complexes are presented as well as their role in the R3SiOTf to R3SiH transformation. The mechanisms of these reactions have been examined by DFT studies, revealing that the active species involved in the reduction of the Si-OTf vs Si-Cl bond are different. The rate-determining transition state is a base-assisted splitting of H2, forming an iridium(III) dihydride species.
Organocalcium Complex-Catalyzed Selective Redistribution of ArSiH3or Ar(alkyl)SiH2to Ar3SiH or Ar2(alkyl)SiH
Li, Tao,McCabe, Karl N.,Maron, Laurent,Leng, Xuebing,Chen, Yaofeng
, p. 6348 - 6356 (2021/05/29)
Calcium is an abundant, biocompatible, and environmentally friendly element. The use of organocalcium complexes as catalysts in organic synthesis has had some breakthroughs recently, but the reported reaction types remain limited. On the other hand, hydrosilanes are highly important reagents in organic and polymer syntheses, and redistribution of hydrosilanes through C-Si and Si-H bond cleavage and reformation provides a straightforward strategy to diversify the scope of such compounds. Herein, we report the synthesis and structural characterization of two calcium alkyl complexes supported by β-diketiminato-based tetradentate ligands. These two calcium alkyl complexes react with PhSiH3 to generate calcium hydrido complexes, and the stability of the hydrido complexes depends on the supporting ligands. One calcium alkyl complex efficiently catalyzes the selective redistribution of ArSiH3 or Ar(alkyl)SiH2 to Ar3SiH and SiH4 or Ar2(alkyl)SiH and alkylSiH3, respectively. More significantly, this calcium alkyl complex also catalyzes the cross-coupling between the electron-withdrawing substituted Ar(R)SiH2 and the electron-donating substituted Ar′(R)SiH2, producing ArAr′(alkyl)SiH in good yields. The synthesized ArAr′(alkyl)SiH can be readily transferred to other organosilicon compounds such as ArAr′(alkyl)SiX (where X = OH, OEt, NEt2, and CH2SiMe3). DFT investigations are carried out to shed light on the mechanistic aspects of the redistribution of Ph(Me)SiH2 to Ph2(Me)SiH and reveal the low activation barriers (17-19 kcal/mol) in the catalytic reaction.
Electrochemical properties of arylsilanes
Biedermann, Judith,Wilkening, H. Martin R.,Uhlig, Frank,Hanzu, Ilie
, p. 13 - 18 (2019/03/27)
In the past, the electrochemical properties of organosilicon compounds were investigated for both fundamental reasons and synthesis purposes. Little is, however, known about the electrochemical behaviour of hydrogen-bearing arylsilanes. Here, we throw light on the electrochemical properties of 11 arylsilanes compounds, 2 of them synthesized for the first time. The oxidation potentials are found to depend on both the nature and number of the aryl groups. Based on these findings it was possible to establish some variation trends that match the expected structure–property correlations. Furthermore, we present first insights into the electrochemical reaction kinetics behind and identify several soluble electrochemical oxidation products.