Orthometallation of N-substituents at the NHC ligand of [Rh(Cl)(COD)(NHC)] complexes: its role in the catalytic hydrosilylation of ketones

Content Provider	Semantic Scholar
Author	Lázaro, Guillermo De León Fernández-Alvarez, Francisco J. Munárriz, Julen Polo, Víctor Iglesias, Manuel Pérez-Torrente, Jesús J. Oro, Luis A.
Copyright Year	2015
Abstract	The rhodium(I)-NHC (NHC = N-heterocyclic carbene) complex [Rh(Cl)(COD)(2-methoxyphenyl-NHC-(CH2)3Si(OiPr)3)] (2a) catalyzes the solvent-free homogeneous hydrosilylation of acetophenone with HSiMe(OSiMe3)2. Kinetic studies show that 2a behaves differently to the related homogeneous catalysts [Rh(Cl)(COD)(R-NHC-(CH2)3Si(OiPr)3)] (R = 2,6-diisopropylphenyl (2b); R = 2-methoxyethyl (2c)). This behavior could be attributable to the participation of different catalytic active species. Indeed, 1H NMR studies of the reaction of 2a with HSiMe(OSiMe3)2 evidenced the formation of a new hydrido-bridged binuclear complex, namely {[Rh(SiMe(OSiMe3)2)(κ-C,C′-R-NHC-(CH2)3Si(OiPr)3)]2(μ-H)2} (R = 2-methoxyphenyl, 3), featuring orthometallated NHC and terminal silyl ligands, which has been proposed as the resting species in the hydrosilylation of acetophenone with HSiMe(OSiMe3)2 catalyzed by 2a. Moreover, the heterogeneous catalyst 2a-MCM-41 evidenced a behavior similar to the homogeneous catalyst 2a in the solvent-free hydrosilylation of acetophenone with HSiMe(OSiMe3)2.
Starting Page	1878
Ending Page	1887
Page Count	10
File Format	PDF HTM / HTML
DOI	10.1039/C4CY01556H
Alternate Webpage(s)	http://www.rsc.org/suppdata/cy/c4/c4cy01556h/c4cy01556h1.pdf
Alternate Webpage(s)	https://pubs.rsc.org/en/content/getauthorversionpdf/C4CY01556H
Alternate Webpage(s)	https://doi.org/10.1039/C4CY01556H
Volume Number	5
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article