2129-30-8Relevant articles and documents
Beyond classical reactivity patterns: Hydroformylation of vinyl and allyl arenes to valuable β- And γ-aldehyde intermediates using supramolecular catalysis
Dydio, Pawe?,Detz, Remko J.,De Bruin, Bas,Reek, Joost N. H.
supporting information, p. 8418 - 8429 (2014/06/24)
In this study, we report on properties of a series of rhodium complexes of bisphosphine and bisphosphite L1-L7 ligands, which are equipped with an integral anion binding site (the DIM pocket), and their application in the regioselective hydroformylation of vinyl and allyl arenes bearing an anionic group. In principle, the binding site of the ligand is used to preorganize a substrate molecule through noncovalent interactions with its anionic group to promote otherwise unfavorable reaction pathways. We demonstrate that this strategy allows for unprecedented reversal of selectivity to form otherwise disfavored β-aldehyde products in the hydroformylation of vinyl 2- and 3-carboxyarenes, with chemo- and regioselectivity up to 100%. The catalyst has a wide substrate scope, including the most challenging substrates with internal double bonds. Coordination studies of the catalysts under catalytically relevant conditions reveal the formation of the hydridobiscarbonyl rhodium complexes [Rh(Ln)(CO)2H]. The titration studies confirm that the rhodium complexes can bind anionic species in the DIM binding site of the ligand. Furthermore, kinetic studies and in situ spectroscopic investigations for the most active catalyst give insight into the operational mode of the system, and reveal that the catalytically active species are involved in complex equilibria with unusual dormant (reversibly inactivated) species. In principle, this involves the competitive inhibition of the recognition center by product binding, as well as the inhibition of the metal center via reversible coordination of either a substrate or a product molecule. Despite the inhibition effects, the substrate preorganization gives rise to very high activities and efficiencies (TON > 18‰000 and TOF > 6000 mol mol-1 h-1), which are adequate for commercial applications.
'backdoor Induction' of chirality: Asymmetric hydrogenation with rhodium(I) complexes of triphenylphosphane-substituted β-turn Mimetics
Kokan, Zoran,Glasovac, Zoran,Majeric Elenkov, Maja,Gredicak, Matija,Jeric, Ivanka,Kirin, Srecko I.
supporting information, p. 4005 - 4015 (2014/11/07)
Bioconjugate bidentate ligands 2-10 were obtained by tethering triphenylphosphanecarboxylic acid to amino acid substituted spacers with different flexibility, ranging from a rigid enediyne-based β-turn inducer to flexible linear aliphatic chains with up to eight carbon atoms. The 21 synthesized ligands revealed up to 81% ee selectivity in rhodium-catalyzed asymmetric hydrogenation of α,β-unsaturated amino acids. The key feature of the catalysts is the prochiral coordination sphere of the catalytic metal while the chirality is transmitted by 'backdoor induction' from distant hydrogen-bonded amino acids. DFT calculations were applied to study the structure and relative stability of the precatalytic organometallic Rh(I) complexes, with particular emphasis on hydrogen-bonded secondary structures.
Catalysts for Suzuki polycondensation: Ionic and "quasi-ionic" amphipathic palladium complexes with self-phase-transfer features
Li, Jing,Fu, Hongwei,Hu, Pan,Zhang, Zilong,Li, Xiao,Cheng, Yanxiang
, p. 13941 - 13944,4 (2020/09/16)
Poly(9,9-dioctylfluorene) (PFO) with Mn values above 100 000 g mol-1 in a toluene/water system and Mn values up to 600 000 g mol-1 in a THF/water system has been obtained by improved Suzuki polycondensation using a new kind of amphipathic palladium catalyst with self-phase-transfer features, which could overcome the disadvantage caused by the immiscible biphasic mixture and accelerate the transmetalation step (see figure). Copyright
Economic large-scale synthesis of o - And m -diphenylphosphinobenzoic acids
Kemme, Susanne T.,Schmidt, Yvonne,Gruenanger, Christian U.,Laungani, Andy C.,Herber, Christian,Breit, Bernhard
experimental part, p. 1924 - 1928 (2010/08/20)
An efficient and simple to perform large-scale synthesis of o- and m-diphenylphosphinobenzoic acids is presented. In a single step, both useful carboxylic acid-functionalized phosphines can be accessed starting from the same inexpensive bulk chemicals o-chlorobenzoic acid, triphenylphosphine, and sodium. In both cases the formation of the desired product is controlled by the ratio of the starting materials only. Additionally, X-ray crystallographic data are reported for both products. Georg Thieme Verlag Stuttgart New York.
Cooperative effect of a classical and a weak hydrogen bond for the metalInduced construction of a self-assembled β-turn mimic
Laungani, Andy C.,Keller, Manfred,Slattery, John M.,Krossing, Ingo,Breit, Bernhard
experimental part, p. 10405 - 10422 (2010/04/05)
A novel metal-induced template for the self-assembly of two independent phosphane ligands by means of unprecedented multiple noncovalent interactions (classical hydrogen bond, weak hydrogen bond, metal coordination, π-stacking interaction) was developed and investigated. Our results address the importance and capability of weak hydrogen bonds (WHBs) as important attractive interactions in selfassembling processes based on molecular recognition. Together with a classical hydrogen bond, WHBs may serve as promoters for the specific self-assembly of complementary monomeric phosphane ligands into supramolecular hybrid structures. The formation of an intermolecular C-H...N hydrogen bond and its persistence in the solid state and in solution was studied by X-ray crystal analysis, mass spectrometry and NMR spectroscopy analysis. Further evidence was demonstrated by DFT calculations, which gave specific geometric parameters for the proposed conformations and allowed us to estimate the energy involved in the hydrogen bonds that are responsible for the molecular recognition process. The presented template can be regarded as a new type of self-assembled β-turn mimic or supramolecular pseudo amino acid for the nucleation of β-sheet structures when attached to oligopeptides.
Synthesis of o-diorganylphosphino-substituted benzoic acids and their derivatives
Veits,Neganova,Vinogradova
, p. 1060 - 1068 (2007/10/03)
o-Substituted dialkyl- and alkylphenylphosphinobenzoic acids, as well as their esters, nitriles, and amides, including those containing three different substituents on the phosphorus atom, were prepared for the first time by two different synthetic procedures. The most general procedure involves metal-halogen exchange in bromo- and iodoarenes, followed by phosphorylation of the resulting lithium derivatives. 2005 Pleiades Publishing, Inc.
Nucleophilic phosphanylation of fluoroaromatic compounds with carboxyl, carboxymethyl, and aminomethyl functionalities - An efficient synthetic route to amphiphilic arylphosphanes
Hingst, Martin,Tepper, Michael,Stelzer, Othmar
, p. 73 - 82 (2007/10/03)
Chiral- and multiply-carboxylated phosphanes and phosphanyl derivatives of benzoic and phthalic acids (1-9) are accessible in high yields by nucleophilic phosphanylation of potassium or lithium salts of commercially available fluorobenzoic and 3-fluorophthalic acids with Ph2PH, Ph2PK, PhPLi2, Ph(K)P-(CH2)3-P(K)Ph in superbasic media (DMSO/KOH) or in THF and DME. The hitherto unknown phosphanylphenylacetic acids (10-13) and phosphanylbenzylamines RR′P-C6H4-CH2-NH2 (14-19, R, R′ = H, Me, Ph) with unsubstituted amino groups were also synthesized by this method. The diphenylphosphanyl derivatives 14-16 (R, R′ = Ph) are accessible by an alternative method involving LiAlH4 reduction of the phosphanylbenzonitriles (20-22), which were obtained in high yields by nucleophilic phosphanylation of the corresponding fluoro- or chlorobenzonitriles. The novel bidentate phosphanylbenzonitrile 23 has also been obtained using this synthetic route. All compounds were completely characterized by elemental analysis, NMR spectroscopy, and mass spectrometry.
Water soluble phosphines VIII. Palladium-catalyzed P-C cross coupling reactions between primary or secondary phosphines and functional aryliodides - A novel synthetic route to water soluble phosphines
Herd, Oliver,Hessler, Antonella,Hingst, Martin,Tepper, Michael,Stelzer, Othmar
, p. 69 - 76 (2007/10/03)
Tertiary phosphines Ph2P-Ar and PhP(Ar)2 containing mono-and disubstituted aromatic ring systems Ar (Ar = C6H4-X and C6H3-XY; X, Y = Me, OH, NH2, COOH, COOMe and SO3Na) are accessible in good yields by Pd(0)-catalyzed cross coupling reactions between diphenylphosphine or phenylphosphine and substituted aryliodides I-C6H4-X or I-C6H3-XY in organic solvents (dimethylacetamide, acetonitrile, methanol) using organic amines or potassium and sodium acetate as bases. If the primary phosphine is employed in the appropriate stoichiometric ratio, functionalized secondary phosphines, e.g. Ph(H)P-C6H4-p-SO3Na, may be obtained selectively.
A new synthesis of hydrophilic carboxylated arylphosphines
Ravindar,Hemling,Schumann,Blum
, p. 841 - 851 (2007/10/02)
An efficient synthetic procedure for the preparation of versatile functionally substituted arylphosphines from commercially available starting materials is reported together with alternative routes for (carboxyphenyl)diphenyl phosphines.
