(NHC)Cu^I (NHC = N-Heterocyclic Carbene) Complexes as Efficient Catalysts for the Reduction of Carbonyl Compounds

Abstract

The hydrosilylation of various ketones is mediated by an imidazolium salt/Cu(I) salt system or by a well-defined (NHC)CuCl (NHC ) N-heterocyclic carbene) catalyst precursor system. Reactions are conducted at room temperature. The synthesis and characterization of well-defined (NHC)CuCl complexes are described.

Synthesis and Characterization of [Cu(NHC)2]X Complexes: Catalytic and Mechanistic Studies of Hydrosilylation Reactions

“…[9] N-Heterocyclic carbenes (NHCs) [10] are an interesting alternative to phosphines for the copper-catalyzed hydrosilylation of carbonyl groups. [CuClA C H T U N G T R E N N U N G (IPr)] (IPr = N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) is an efficient catalyst for the hydrosilylation of unhindered ketones [11] and for the conjugate reduction of tri-and tetra-substituted a,b-unsaturated ketones and esters. [12] More challenging ketones can be hydrosilylated in the presence of [CuClA C H T U N G T R E N N U N G (ICy)] (ICy = N,N'-bis(cyclohexyl)imidazol-2-ylidene) or [CuClA C H T U N G T R E N N U N G (SIMes)] (SIMes = N,N'-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene).…”

NEWLY DEVELOPED ANCHORED Ru(II)-N-HETEROCYCLIC CARBENE COMPLEX AND ITS APPLICATIONS

“…[1,2,3] N-heterocyclic carbene complexes represent a very useful family of organo-metallic complexes, which can catalyze a great deal of important reactions, among others: hydrogenation, hydrogen-transfer, hydrosilylation, hydroformylation and C-C coupling reactions. [3][4][5][6] A new water-soluble Ru-N-heterocyclic carbene (NHC) complex was recently prepared and applied in the hydrogenation of various starting materials, such as alkenes, aldehydes and ketones. [7] The …”

Post‐Synthesis Functionalization of (Meth)acrylate Based Monoliths via Electron Beam Triggered Graft Polymerization

“…Such an exchange has been suggested earlier. [29,30] M. J. Beier, W. Knolle, A. Prager-Duschke, M. R. Buchmeiser Scheme 2. Synthesis of monolith-immobilized Cu(I)-NHC complexes 10 and 11.…”