Wasserlösliche Phosohane, XIV. Hydrophile Derivate des Triphenylphosphans mit NH_2-, COOH- und P(O)(OR)₂-funktionalisierten Seitenketten / Water Soluble Phosphanes, XIV. Hydrophilic Derivatives of Triphenylphosphane with NH₂, COOH and P (O)(OR)₂ Functionalized Side Chains

Abstract

Nucleophilic phosphanylation of orf/zo-fluorophenylacetic acid or orf/jofluorobenzylamine with PhPH2 using KOfBu as the base affords the hydrophilic tertiary phosphanes 3 and 4a with terminal CH2-COOH and CH2-NH2 substituents. The corresponding secondary phosphane li gands 2 or 5 may be obtained by Pd-catalyzed P-C coupling of orr/20-iodophenylacetic acid with PhPH2 or selective nucleophilic phosphanylation of orf/jo-fluorophenylacetic acid. Novel phosphonatomethyl derivatives 7a, 7b of triphenylphosphane have been obtained in a two sta ge synthesis using orf/zo-iodobenzylchloride or w^ta-iodobenzylbromide as starting materials. Arbusov reaction with P(OEt)3 and Pd-catalyzed P-C coupling reactions with Ph2PH gave the esters 7a, 7b. Purification of 7a was achieved via its BH3 adduct 8a. Deprotection, hydrolysis and neutralisation with NaOH affords the water soluble sodium salts 9a,9b. a-Hydroxy and a-benzylamino derivatives 12 and 14 of orr/zo-diphenylphosphanobenzyl phosphonate (e.g. 7a) and the corresponding Me2P (0) analogs 13 and 16 are accessible in a straightforward man ner by addition of (M e0)2P(0)H or Me2P(0)H to orf/?o-phosphanobenzaldehyde 11a or its benzaldimino derivative 15, respectively. An improved synthesis for lla -llc has been develo ped. Reaction of 11a with the Wittig reagent Ph3P=C(H)COOEt and subsequent hydrolysis of the intermediate ester 17a affords o/t/?o-diphenylphosphano cinnamic acid 17. The catalytical activity of 1,9a, 9b and related ligands in Suzuki-type coupling reactions has been investigated. Derivate des Triphenylphosphans mit COOHund P (0 )(0 R )2-Gruppen (z.B. A [2], B [3]) sind als Katalysatorliganden für die Hydrofor mylierung und Oligomerisation von Olefinen [4] sowie die Carbonylierung von Benzylhalogeni den in Zweiphasensystemen [3] von Bedeutung. Durch Immobilisierung aromatischer Phosphane mit P (0 )(0 R )2-Resten (B) an anorganischen Ma terialien (Zirconium(IV)-phosphat, -phosphonat, -phosphit) wurden geträgerte Katalysatoren erhal ten, die für Hydroformylierungs-und Heck-Reaktionen in heterogenen Systemen mit Erfolg einge setzt wurden [5, 6]. Die Einschiebung einer CH(Z)-Brücke in A und B führt zu Liganden C bzw. D mit flexibler

Synthesis and coordination properties of palladium(II) and platinum(II) complexes with phosphonated triphenylphosphine derivatives

“…The ligand design promises similar coordination behaviour and catalytic activity as is known for triphenylphosphine, good solubility in water and flexible strong attachment to a solid surface. The ortho and meta isomers of 3a and 4a (and their disodium salts) were already reported by Liek et al [7] having been used as catalysts in Pd-catalysed Suzuki coupling under biphasic conditions with satisfactory results. Later, also the para isomer has been mentioned [14] in a set of phosphanyl-phosphonates (including 4a and its disodium salt) and experiments on Rh-catalyzed hydroformylation were performed, but no details on characterization of the complexes were mentioned and no attention to Pd(II) and Pt(II) chemistry was paid.…”

“…The last reaction required at least two-fold molar excess of NaP(O)(OEt) 2 for complete substitution; the residual reagent was then removed by extraction with 2% (w/w) aqueous NaOH solution. Out of a variety of reactions introducing the phosphanyl group into the molecule [18] we chose a mild Pd-catalyzed P-C cross-coupling reaction employing the reaction conditions similar to those already used [7,19]. In this reaction diphenylphosphine is used; we have summarized the synthetic methods for its preparation [20] and proposed a simplified procedure, in which we reduced the volume of solvents, avoided unnecessary drying and deoxygenation procedures and minimized the number of extraction and washing steps [21].…”

“…The use of secondary amines as the deprotection agent was not suitable for our purpose because of possible interaction with the phosphonate group and, also, a rather inconvenient separation of the amine-borane adduct from the deprotected ligand (filtration through alumina column [24] or vacuum sublimation [7]). Both general methods reported in literature (deprotection with a mixture of 4 Å molecular sieve, aliphatic alcohol and cyclic ether [25] and deprotection using HBF 4 AE OMe 2 in dichloromethane [26]) were successful and we chose the later one for its simplicity.…”

“…Ambitions to use various ''field-proven'' homogeneous catalysts under aqueous and biphasic conditions made for the synthesis of a vast amount of phosphines modified by hydrophilic groups such as ammonium and phosphonium (cationic), sulfonate, phosphonate and carboxylate (anionic) or alcohol and polyether chain (neutral) [1]. Phosphines modified by phosphonate moiety [2] have been attracting attention as alternatives to well-established sulfonates [1]; several examples of their use in biphasic catalysis have been mentioned in literature [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] (e.g., Pd-catalysed electrochemical reduction of CO 2 [3], Rh-catalysed carbon-carbon double bond hydrogenation or hydroformylation [4,5], Pd-catalysed benzyl halide carbonylation [6] and Suzuki coupling [7]). A great advantage (compared with other hydrophilic moieties) is the possibility to bind the phosphonated ligand to an inert oxide surface (e.g., Al 2 O 3 ) [8], onto activated carbon surface [9] or into a layered framework, e.g., zirconium phosphonate [10,12] or zirconium phosphite/phosphonate hybrid material [13].…”

Neutral palladium(II) complexes with P,N Schiff-base ligands: Synthesis, characterization and catalytic oligomerisation of ethylene

“…All reagents were purchased from Aldrich and used without further purification. 2-Diphenylphosphinobenzaldehyde [56], Pd(COD)Cl 2 [57], and ligand 1e [58] were prepared by published procedures. Melting points were recorded on a Kofler hotstage microscope (Reichert Thermovar).…”