4-Diphenylphosphinobenzoic acid

The chain-growth catalyst is prepared by dissolving two moles of nickel chloride per mole of bidentate ligand (BDL) (diphenylphosphinobenzoic acid in 1,4-butanediol). The mixture is pressurized with ethylene to 8.8 MPa (87 atm) at 40°C. Boron hydride, probably in the form of sodium borohydride, is added at a molar ratio of two borohydrides per one atom of nickel. The nickel concentration is 0.001—0.005%. The 1,4-butanediol is used to solvent-extract the nickel catalyst after the reaction. 

Palladium/charcoal also could serve as a catalyst for Sonogashira reactions of peptides in aqueous media. Recently, Granja et al. used palladium/carbon associated with 4-diphenylphosphinobenzoic acid (4-DPPBA) or triphenylphosphine ligand to catalyze such a reaction in aqueous DMF (Eq. 4.16).34... 

A further reaction of [Ir(cod)Cl]2 with 3,4-dimethylphosphaferrocene, (355), yields the trigonal-bipyramidal complex [Ir(355)3(cod)]BF4, (356). 79 (356) reacts with H2 under pressure to give [Ir(355)4H2]+. Reaction of Ir(cod)Cl]2 with o-diphenylphosphinobenzoic acid ethyl ester (dpes), (357), yields [IrCl(cod)(dpes)], where dpes is acting as a monodentate P-donor-atom ligand.580 When dpes is reacted with [Ir(cod)2]BF4, then the structurally determined... 

An excellent review21 outlining the mechanism of diphenylphosphinobenzoic acid-based palladium-catalysed asymmetric substitution of allyl compounds with nucleophiles has been published. The mechanistic model developed for these reactions allows one to predict the stereochemistry of the product(s). 

The oligomerization reaction is believed to involve a nickel hydride, which is generated in situ from nickel(O), triphenylphosphine, and the phenyl ester of o-diphenylphosphinobenzoic acid. The trimerization of ethylene to 1-hexene is described in Figure 14. 

The oligomerization reaction is carried out in a polar solvent in which the nickel catalyst is dissolved but the nonpolar products, the a-olefins, are nearly insoluble. Preferred solvents are alkanediols, especially 1,4-butanediol. This was one of the first examples of a biphasic liquid/liquid system to be used in catalysis and is one of the key features of the process. The nickel catalyst is prepared in situ from a nickel salt, e.g., nickel chloride, and a chelating PnO ligand like o-diphenylphosphinobenzoic acid (Structure 1) by reduction with sodium boro-hydride [30, 39]. Suitable ligands are the general type of diorganophosphino acid derivatives (2). 

Wittig reactions Carbomethoxymethylenetriohenylphosphorane. Cyclopropyltriphenyl-phosphonium bromide. l,5-Diazabicyclo[4.3.0]nonene-5. Diethyl cyanomethylphosphonate. p-Diphenylphosphinobenzoic acid. Diphenylsulfonium isopropylide. Diphenyl triphenyl-phosphoranylidenemethylphosphonate. Ethyl(dimethylsulfuranylidine)acetate. Ethylene oxide. Hexamethylphosphorous triamide. Methoxymethylenetriphenylphosphorane. Meth-ylenemagnesium bromide (chloride). Simmons-Smith reagent. Sodium 2-methyl-2-butoxide. 

Diphenylmercury, 31 Diphenylmethane, 343 p-(Diphenylmethyl)diphenylhydroxy-methylbenzene, 454 1,8-Diphenylnaphthalene, 112 2,4-Diphenylnaphthoresorcinol, 345 9,10-Diphenylphenanthrene, 79 Diphenylphosphide, 179 p-Diphenylphosphinobenzoic acid, 179 p-Diphenylphosphinylbenzoic acid, 179 Diphenyl phosphorochlorodate, 180, 322 Diphenyl sulfide, 180, 358 Diphenylsulfonium isopropylide, 180-181 Diphenyl sulfoxide, 99... 

Two stereogenic centers are established on allylation of a-substituted P-keto esters and cyanoacetic esters with secondary cinnamyl acetates. The reaction is directed toward a regio-selective and diastereoselective pathway when o-diphenylphosphinobenzoic acid is used as a hgand. ... 

Allylation. Linear products are obtained from the Ru-catalyzed allylation of active methylene compounds (deprotonated by LiHMDS) with either primary or secondary allylic acetates. A suitable ligand for the Ru metal is o-diphenylphosphinobenzoic acid. 

Johnson Matthey have shown very recently that amphiphilic reagents such as dodecyltrimethylammonium bromide can have a significant effect on activity. Rh/4-diphenylphosphinobenzoic acid catalysts in water were active for the hydroformylation of a range of alk-l-enes at 80°C and 0.56 MPa. Selectivities of 100 and efficiencies of > 90% were obtained for the hydroformylation of hex-l-ene with low Rh losses. This system gave similar rates to those given by the Rhone Poulenc catalyst under lower H2/CO pressures (0.56 vs. 4 MPa). 

Cuprous chloride tends to form water-soluble complexes with lower olefins and acts as an IPTC catalyst, e.g., in the two-phase hydrolysis of alkyl chlorides to alcohols with sodium carboxylate solution [10,151] and in the Prins reactions between 1-alkenes and aqueous formaldehyde in the presence of HCl to form 1,3-glycols [10]. Similarly, water-soluble rhodium-based catalysts (4-diphenylphosphinobenzoic acid and tri-Cs-io-alkylmethylam-monium chlorides) were used as IPTC catalysts for the hydroformylation of hexene, dodecene, and hexadecene to produce aldehydes for the fine chemicals market [152]. Palladium diphenyl(potassium sulfonatobenzyl)phosphine and its oxide complexes catalyzed the IPTC dehalogenation reactions of allyl and benzyl halides [153]. Allylic substrates such as cinnamyl ethyl carbonate and nucleophiles such as ethyl acetoactate and acetyl acetone catalyzed by a water-soluble bis(dibenzylideneacetone)palladium or palladium complex of sulfonated triphenylphosphine gave regio- and stereo-specific alkylation products in quantitative yields [154]. Ito et al. used a self-assembled nanocage as an IPTC catalyst for the Wacker oxidation of styrene catalyzed by (en)Pd(N03) [155]. 

In the case of the phenyl ligand we need to improve the synthesis of the phosphine component, o-diphenylphosphinobenzoic acid, develop a scalable coupling method, and... 

Pd on carbon and Cul, combined with phosphine ligands, are used as good catalysts in some cases. The coupling of Al-propargylamino acid 20 with 3-bromopyridine proceeded in an aqueous phase to give 21. Pd on carbon and water-soluble diphenylphosphinobenzoic acid (II-3) were used [26]. 

Trost designed chiral diamides of 2-diphenylphosphinobenzoic acid (DPPBA) and 2-diphenylphosphinoaniline (DPPA), and their derivatives (abbreviated as Trost L-1, L-2, L-3, L-4, and L-5), which are remarkably effective ligands in asymmetric allylations as described later. 

The entire process is schematized on Figure 4. In the first step, ethylene is oligomerized in the presence of a homogeneous nickel phosphine catalyst. This catalyst is a nickel hydride generated by reduction of a nickel salt in the presence of a chelating ligand such as diphenylphosphinobenzoic acid or by reaction of nickel(O) with a phosphorus ylide. 

This reaction has been nsed in the preparation of a series of pharmacologically active amines [ 104] and diamines [105]. A stereoselective version of this reaction by nsing the directing group o-diphenylphosphinobenzoic acid has been reported [ 106] (Figure 27). 

Achard and co-workers reported the development of an Ir-catalyzed reaction for the formation of julolidines via a cyclization step involving a hydrogen transfer reaction with 1,3-propanediol and tetrahydroquinoline. In a representative example, 1,3-propanol (1 equiv) was reacted with 1,2,3,4-tetrahydroquinoline (2 equiv) in the presence of [Cp IrCl2]2 (1 mol%) combined with diphenylphosphinobenzoic acid (DPPBA) (2 mol%) in toluene at 130 °C to give julolidine in 91 % yield (Scheme 42) [235]. This reaction proceeded via the formation of an enaminoi-minium intermediate. 

Phospinoxides continue to he examined as photoinitiators, known for the optimal cleavage even in rather thick layers. Un-activated al-kenes have been hydrophosphinylated in good yields by irradiation in the presence of diatylphosphine oxides and commercially available dyes as photocatalysts. Some heterohelicenes have been prepared by oxidative photocyclization of the corresponding phosphindole-benzophenan-threne. The SrnI reaction has been extended to the preparation of diphenylphosphinobenzoic acid by photostimulation of the chlorobenzoate ion in the presence of diphenylphosphine anion in liquid ammonia. Diphenylphosphines have been also prepared by photostimulated substitution of 7-bromonorbornadiene and derivatives. ... 

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