40927-83-1Relevant academic research and scientific papers
Efficient Pd-Catalyzed Allene Synthesis from Alkynes and Aryl Bromides through an Intramolecular Base-Assisted Deprotonation (iBAD) Mechanism
Nella, Natalie,Parker, Evelyne,Hitce, Julien,Larini, Paolo,Jazzar, Rodolphe,Baudoin, Olivier
, p. 13272 - 13278 (2014)
An optimized ligand-controlled palladium-catalyzed allene synthesis starting from alkynes and aryl bromides giving rise to allene products in a simple and direct manner is described. The methodology is performed in an inter- and intramolecular fashion wit
5,16-Dialkyl(diaryl)-5,16-dihydro-5,16-diphospha-tetraepoxy[22]annulene (2.1.2.1)
M?rkl, Gottfried,Amrhein, Jürgen,Stoiber, Thomas,Striebl, Ulrich,Kreitmeier, Peter
, p. 2551 - 2567 (2007/10/03)
Several 5,16-dialkyl(diaryl)-5,16-dihydro-5,16-diphospha-tetraepoxy[22]annulenes (2.1.2.1) 9 as possible precursors of aromatic 5,16-diphospha-tetraepoxy[22]annulenes(2.1.2.1) 8 are synthesized by cyclizing Wittig-reactions of the phosphane dialdehydes 15 with the bis-ylids of the phosphane-bisphosphoniumsalts 19.
A Wittig reaction with 2-furyl substituents at the phosphorus atom: Improved (Z) selectivity and isolation of a stable oxaphosphetane intermediate
Appel, Marco,Blaurock, Steffen,Berger, Stefan
, p. 1143 - 1148 (2007/10/03)
Wittig reactions with ylides bearing one, two or three 2-furyl groups directly bound to the phosphorus atom have been studied. Greatly improved (Z)-alkene selectivities of up to 98:2 could be observed if 2-furyl groups were present. Monitoring of the reactions by NMR spectroscopy revealed only oxaphosphetane intermediates, which became more stable with increasing number of 2-furyl substituents bound to the phosphorus atom. Oxaphosphetane 10d, with three furyl groups, was successfully isolated, and the results of a crystal structure analysis are presented. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Water-soluble derivatives of furylphosphanes
Eymery, Frederic,Burattin, Paolo,Mathey, Francois,Savignac, Philippe
, p. 2425 - 2431 (2007/10/03)
(2-Furyl)diphenylphosphane (1), bis(2-furyl)phenylphosphane (8) and tris(2-furyl)phosphane (9) have been converted into their water soluble 5- carboxylates 4, 11 and 12, 5-phosphonates 14 and 16 and 5-sulfinates 17-19. In most cases, the selected route involved a 5-bromo to 5-lithio exchange reaction, followed by reaction with CO2, CIP(O)(OEt)2 or SO2. The furan group sharply enhances the water-solubility of these products when compared with the corresponding benzene derivatives. Catalytic tests in hydrogenation, hydroformylation and Heck cross-coupling reactions showed that the sulfinate group tends to inhibit the catalysis and, in addition, a sharp drop in activity was observed with the trifunctional products 12 and 10. Overall, the phosphonates 14 and 16 appear to be the most promising ligands for biphasic catalysis.
Novel Basic Ligands for the Homogeneous Catalytic Homologation of Methanol to Ethanol, II. Synthesis and Complex Chemical Behaviour of Potential Bi- and Tridentate P-N and P-O Containing Chelate Ligands
Lindner, Ekkehard,Rauleder, Hartwig,Scheytt, Christoph,Mayer, Hermann August,Hiller, Wolfgang,et al.
, p. 632 - 642 (2007/10/02)
Tridentate P-N and P-O ligands of the type RP(XC5H4N)2 (1a, b, a', b') and PhP(CH2C4H7O)2 (1c'') are obtained by reaction of RPCl2 with 2-hydroxy- and 2-aminopyridine and Li2PPh with tetrahydrofurfuryl chloride, respectvely.In a similar way the potential bidentate ligand Ph2PCH2C4H7O (2c'') is formed by the action of LiPPh2 on ClCH2C4H7O.Potential tridentate ligands as RP(C4H3O)2 (3a'''-c''') with two furyl-phosphorus bonds can be isolated from RPCl2 and furyllithium.The complex chemical behaviour towards Mo(CO)6 or carbonyl derivatives of chromium was elucidated for 2c''' and 3a'''-c''', resulting in the formation of (OC)5MoPPh2CH2C4H7O (4c'') and trans-(OC)4Cr2 (5a'''-c'''), respectively.In the case of 5a''' an X-ray investigation proved 3a'''-c''' to be only monodentate P-ligands. 5a''' crystallizes in the monoclinic space group P21/c with Z = 2. 1c'' is the most versatile species within this series and functions probably as tri-, bi- and monodentate P-O ligand.With 1c'' and 3c''' some homologation experiments of methanol at 200 deg C and 304 bar synthesis gas pressure were carried out. - Key words: Tri- and Bidentate P-N and P-O Ligands, Complexes of Cr, Mo, Structure of trans-(OC)4Cr2, NMR Spectra
