112473-30-0Relevant academic research and scientific papers
Grafting of Copper(I)-NHC Species on MCM-41: Homogeneous versus Heterogeneous Catalysis
Garcs, Karin,Fernndez-Alvarez, Francisco J.,Garca-Ordua, Pilar,Lahoz, Fernando J.,Prez-Torrente, Jess J.,Oro, Luis A.
, p. 2501 - 2507 (2015)
The copper(I) complexes [Cu(X){2,6-diisopropylphenyl-NHC-(CH2)3Si(OiPr)3}] (X=Cl (2a); I (2b), NHC=N-heterocyclic carbene) have been synthesized and characterized. Furthermore, the structure of 2b has been confirmed by X-r
Cu(I)-N heterocyclic carbene complexes: Synthesis, catalysis and DFT studies
Dinda, Joydev,Roymahapatra, Gourisankar,Sarkar, Deblina,Mondal, Tapan K.,Al-Deyab, Salem S.,Sinha, Chittaranjan,Hwang, Wen–Shu
, p. 449 - 456 (2017)
The structural, spectroscopic and catalytic properties of the two Cu(I) complexes [Cu2(L1)2](PF6)2;(1) and [Cu2(L2)2](PF6)2; (2), bearing proligands 2,6-bis-(N-methyli
Syntheses of Sterically Bulky Schiff-Base Magnesium Complexes and Their Application in the Hydrosilylation of Ketones
Ma, Mengtao,Shen, Xingchao,Wang, Weifan,Li, Jia,Yao, Weiwei,Zhu, Lijun
, p. 5057 - 5062 (2016)
The sterically bulky Schiff-base ligand 1 (L1H) was treated with CH3MgI in toluene to give the unexpected homoleptic magnesium complex 2 (L1MgL1) in good yield. However, the reaction of sterically more bulky lig
HOMOGENEOUS CATALYSIS VIII. CARBENE-TRANSITION-METAL COMPLEXES AS HYDROSILYLATION CATALYSTS
Lappert, Michael F.,Maskell, Robin K.
, p. 217 - 228 (1984)
Some carbene-transition-metal complexes, particularly those of rhodium(I) but also of ruthenium(II), have proved to be effective catalysts for the hydrosilylation (e.g., using SiHEt3 or SiH2Ph2) of ketones (to afford silyl ethers) or alkynes.The addition
Rhodium-Catalyzed Dehydrogenative Silylation of Acetophenone Derivatives: Formation of Silyl Enol Ethers versus Silyl Ethers
Garcés, Karin,Lalrempuia, Ralte,Polo, Víctor,Fernández-Alvarez, Francisco J.,García-Ordu?a, Pilar,Lahoz, Fernando J.,Pérez-Torrente, Jesús J.,Oro, Luis A.
, p. 14717 - 14729 (2016)
A series of rhodium–NSiN complexes (NSiN=bis (pyridine-2-yloxy)methylsilyl fac-coordinated) is reported, including the solid-state structures of [Rh(H)(Cl)(NSiN)(PCy3)] (Cy=cyclohexane) and [Rh(H)(CF3SO3)(NSiN)(coe)] (coe=cis-cyclooctene). The [Rh(H)(CF3SO3)(NSiN)(coe)]-catalyzed reaction of acetophenone with silanes performed in an open system was studied. Interestingly, in most of the cases the formation of the corresponding silyl enol ether as major reaction product was observed. However, when the catalytic reactions were performed in closed systems, formation of the corresponding silyl ether was favored. Moreover, theoretical calculations on the reaction of [Rh(H)(CF3SO3)(NSiN)(coe)] with HSiMe3and acetophenone showed that formation of the silyl enol ether is kinetically favored, while the silyl ether is the thermodynamic product. The dehydrogenative silylation entails heterolytic cleavage of the Si?H bond by a metal–ligand cooperative mechanism as the rate-determining step. Silyl transfer from a coordinated trimethylsilyltriflate molecule to the acetophenone followed by proton transfer from the activated acetophenone to the hydride ligand results in the formation of H2and the corresponding silyl enol ether.
Cationic Dirhodium Complexes Bridged by 2-Phosphinopyridines Having an Exquisitely Positioned Axial Shielding Group: A Molecular Design for Enhancing the Catalytic Activity of the Dirhodium Core
Ohnishi, Ryuhei,Ohta, Hidetoshi,Mori, Shigeki,Hayashi, Minoru
, p. 2678 - 2690 (2021/07/31)
This report describes a strategy to create highly electrophilic dirhodium catalysts. The electrophilicity of lantern-Type dirhodium complexes is generally decreased by the coordination of a ligand to the axial site, which often causes a reduction in the catalytic activity. We designed and synthesized a series of cationic dirhodium complexes bridged by 2-diarylphosphinopyridines having a bulky 2,4,6-Triisopropylphenyl (Tip) group that can prevent the attack of external molecules to the closest axial site. Theoretical calculations indicated that the Tip group weakly interacts with the axial site but hardly reduces the electrophilicity of the dirhodium core. The complexes served as excellent catalyst precursors for the dehydrogenative silylation of alcohols using hydrosilanes under mild conditions and a low metal loading, producing the silyl ethers in higher yields in comparison to conventional dirhodium complexes.
Reversible Silylium Transfer between P-H and Si-H Donors
Belli, Roman G.,Pantazis, Dimitrios A.,McDonald, Robert,Rosenberg, Lisa
supporting information, p. 2379 - 2384 (2020/12/07)
The Mo=PR2 π* orbital in a Mo phosphenium complex acts as acceptor in a new PIII-based Lewis superacid. This Lewis acid (LA) participates in electrophilic Si-H abstraction from E3SiH to give a Mo-bound secondary phosphine ligand, Mo-PR2H. The resulting Et3Si+ ion remains associated with the Mo complex, stabilized by η1-P-H donation, yet undergoes rapid exchange with an η1-Si-H adduct of free silane in solution. The equilibrium between these two adducts presents an opportunity to assess the role of this new LA in catalytic reactions of silanes: is the LA acting as a catalyst or as an initiator? Preliminary results suggest that a cycle including the Mo-bound phosphine-silylium adduct dominates in the catalytic hydrosilylation of acetophenone, relative to a putative cycle involving the silane-silylium adduct or “free” silylium.
The synthesis, properties, and reactivity of Lewis acidic aminoboranes
Bentley, Jordan N.,Simoes, Selvyn A.,Pradhan, Ekadashi,Zeng, Tao,Caputo, Christopher B.
supporting information, p. 4796 - 4802 (2021/06/11)
The evolution of frustrated Lewis pair chemistry has led to significant research into the development of new Lewis acidic boranes. Much of this has focused on modifying aryl substituents rather than introducing heteroatoms bound to boron. We recently reported that bis(pentafluorophenyl)phenothiazylborane (1) could be used as a Lewis acid catalyst for the heterolytic dehydrocoupling of stannanes. In this work, we synthesize and characterize a family of Lewis acidic aminoboranes and explored their reactivity with various Lewis bases as well as their efficacy as catalysts for stannane dehydrocoupling and hydrosilylation. Quantum chemical calculations were undertaken to understand the origins of the Lewis acidity and the most Lewis acidic aminoborane (5) was found to be an effective catalyst even in coordinating solvents such as water or acetonitrile, suggesting the amino substituent provides a level of protection against competing donors.
Light-Promoted Transfer of an Iridium Hydride in Alkyl Ether Cleavage
Fast, Caleb D.,Schley, Nathan D.
supporting information, p. 3291 - 3297 (2021/10/12)
A catalytic, light-promoted hydrosilylative cleavage reaction of alkyl ethers is reported. Initial studies are consistent with a mechanism involving heterolytic silane activation followed by delivery of a photohydride equivalent to a silyloxonium ion generated in situ. The catalyst resting state is a mixture of Cp*Ir(ppy)H (ppy = 2-phenylpyridine-κC,N) and a related hydride-bridged dimer. Trends in selectivity in substrate reduction are consistent with nonradical mechanisms for C-O bond scission. Irradiation of Cp*Ir(ppy)H with blue light is found to increase the rate of hydride delivery to an oxonium ion in a stoichiometric test. A comparable rate enhancement is found in carbonyl hydrosilylation catalysis, which operates through a related mechanism also involving Cp*Ir(ppy)H as the resting state.
Rhodium(I) complexes with N-heterocyclic carbene ligands: synthesis, biological properties and catalytic activity in the hydrosilylation of aromatic ketones
Hamdi, Naceur,Slimani, Ichraf,Mansour, Lamjed,Alresheedi, Faisal,?zdemir, Ismail,Gürbüz, Nevin
, p. 2558 - 2579 (2021/10/23)
New rhodium(I) N-heterocyclic carbene (NHC) complexes 3a–f were synthesized in good yields by the reactions of rhodium dimer [Rh(OMe)(cycloocta-1,5-diene:COD)]2 with benzimidazolium salts 2a–f in tetrahydrofuran. All the complexes were characte
