18402-75-0Relevant academic research and scientific papers
New hybrid bidentate ligands as precursors for smart catalysts
Goettmann, Frederic,Boissiere, Cedric,Grosso, David,Mercier, Francois,Le Floch, Pascal,Sanchez, Clement
, p. 7416 - 7426 (2005)
1-Phosphanorbornadiene derivatives were grafted onto various periodically organized mesoporous powders, including a new zirconia/silica mixed oxide synthesized by aerosol techniques. After complexation with the [Rh(CO) 2]+ fragment, these materials were revealed to be more active in olefin hydrogenation than their homogeneous counterparts. The reasons for this higher activity are discussed in the light of theoretical modeling. Various surface treatments, such as esterification, drying, and functionalization with PhSi(OEt)3, provided insights into the nature and mechanism of formation of the active species. Zirconia-based materials were found to be active in internal olefin hydroformylation. Investigation of the mechanism of this reaction shows that the isomerization step is catalyzed by the Lewis acidic support, whereas the hydroformylation step is driven by the rhodium catalyst. Dissociation of these two steps leads to enhancement of activity.
PALLADIUM ACYCLIC DIAMINOCARBENE COMPLEXES AS PRECATALYSTS FOR HIYAMA COUPLING AND THE TANDEM ONE-POT FLUORIDE FREE HIYAMA COUPLING/CYCLIZATION FOR THE SYNTHESIS OF BIOLOGICALLY RELEVANT
-
Paragraph 0072-0074, (2020/05/06)
The present invention provides Acyclic diaminocarbene complex of formula (I): Wherein, M is palladium; X is monoanionic ligand selected from Cl, Br or I; Where R1 is different from R2; R1 is selected from the group consisting of alkyl or aryl, each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms; R2 is selected from the group consisting of alkyl, or aryl each of which have 4 to 20 carbon atoms, and may optionally contain one or more heteroatoms. The said palladium diamino carbine complex of the present invention are particularly useful as catalyst from Hiyama cross-coupling reaction.
Dehydrogenative Coupling of Terminal Alkynes with O/N-Based Monohydrosilanes Catalyzed by Rare-Earth Metal Complexes
Guo, Dianjun,Huang, Zeming,Pan, Mengke,Sheng, Tian,Wang, Shaowu,Zha, Ling,Zhou, Shuangliu,Zhu, Xiancui
supporting information, p. 14152 - 14161 (2020/10/09)
Newly synthesized rare-earth metal alkyl complexes bearing a tripyrrolyl ligand act as excellent precatalysts for the cross-dehydrogenative coupling between various terminal alkynes and O/N-based monohydrosilanes of HSi(OEt)3/HSi(NMe2)3, leading to the formation of a variety of alkoxysilylalkyne and aminosilylalkyne derivatives in good to high yields. The precatalysts LRE(CH2SiMe3)(thf)2 (RE = Y(1a), Er(1b), Yb(1c), L = 2,5-[(2-C4H3N)CPh2]2(C4H2NMe), thf = tetrahydrofuran) were easily prepared in high yields via the reactions of RE(CH2SiMe3)3(thf)2 with the proligand H2L in a single step. Mechanistic studies reveal that treatment of 1 with phenylacetylene could generate the active catalytic species: dinuclear rare-earth metal alkynides (L(thf)n[RE(μ-CCPh)]2L) (RE = Y(5a), n = 1; Yb(5c), n = 0), which could react with HSi(OEt)3 to produce the coupling product 4aa and the dinuclear rare-earth metal hydrides (L (thf)[RE(μ-H)]2L) (RE = Y(6a); Yb(6c)). By contrast, prior treatment of 1c with HSi(OEt)3 proceeds via cleavage of the Si-O bond to produce the dinuclear ytterbium alkoxide (LYb(μ-OEt))2 7c, which is inert in the dehydrogenative coupling reaction. The results of the mechanistic studies are consistent with the observation that the reaction is greatly influenced by the addition sequence of precatalyst/alkynes/silanes.
Catalysed stereodivergent hydrosilylation with Onium Salts stabilised M(0) nanocatalysts prepared in scCO2
Pascu,Liautard,Vaultier,Pucheault,Aymonier
, p. 59953 - 59960 (2015/02/19)
M(0) nanocatalysts stabilised in Onium Salt were synthesised using an original preparation and their effectiveness in catalysing the challenging selective sterodivergent alkyne hydrosilylation reaction was studied. Four metal based nanocrystals, namely Pt
Heterogeneously catalyzed aerobic cross-dehydrogenative coupling of terminal alkynes and monohydrosilanes by gold supported on oms-2
Yamaguchi, Kazuya,Wang, Ye,Oishi, Takamichi,Kuroda, Yoshiyuki,Mizuno, Noritaka
supporting information, p. 5627 - 5630 (2013/06/27)
Cross-dehydrogenative coupling of various terminal alkynes and monohydrosilanes efficiently proceeded in the presence of gold supported on OMS-2 (Au/OMS-2) using O2 as a terminal oxidant, affording the corresponding alkynylsilanes in moderate to high yields (see picture). The observed catalysis was truly heterogeneous, and the catalyst could be reused at least ten times without a significant loss of its high catalytic performance. Copyright
Lewis base-catalyzed additions of alkynes using trialkoxysilylalkynes
Lettan II, Robert B.,Scheidt, Karl A.
, p. 3227 - 3230 (2007/10/03)
(Chemical Equation Presented) The Lewis base-catalyzed additions of alkynyl nucleophiles to aldehydes, ketones, and imines is described. Mechanistic studies strongly indicate that the use of new triethoxysilylalkynes facilitates access of a reactive hyper
New P∧O ligand grafted on periodically organised mesoporous silicas for one-pot bifunctionnal catalysis: Coupling of base catalysed Knoevenagel condensation with in situ Rh catalysed hydrogenation
Goettmann, Frederic,Grosso, David,Mercier, Francois,Mathey, Francois,Sanchez, Clement
, p. 1240 - 1241 (2007/10/03)
The 1-phosphanorbornadiene-rhodium complex (Rh-PNBD) anchored on a mesostructured porous silica matrix is the first example of a rhodium center chelated by a phosphorus and an oxygen atom belonging to the anchoring siloxane moiety. These new hybrid silicas behave as very active recyclable hydrogenation catalysts, which combined with additional grafted amino functions allow efficiently driven one-pot bifunctionnal catalysis.
