Phosphine, tris -tolyl-complexes with

Tri(f-butyl)phosphine and tri(o-tolyl)phosphine form 1 1 complexes with mercury(II) halides and with Hg(SCN)2. Physicochemical measurements, Le. conductance, molecular weight determinations, IR and Raman spectra, indicate a dimeric structure (26) of Cy, skeletal symmetry.493... 

It was shown that palladacydes 1 [3c, 24] prepared from palladium] I) acetate and tris(o-tolyl)- or trimesitylphosphine are excellent catalysts for the Heck coupHng of triflates and halides including certain aryl chlorides. In some of these cases, a possible involvement of oxidation states +II and +IV in the catalytic cycle has been considered [25]. Similarly, other palladacydes such as 3 [26e,h] or 6 [27] have been used in the Heck reactions (Figure 8.1) [24, 26, 28]. It has been proposed that, at least for NC palladacydes, the reaction proceeds through the classical phosphine-free Pd(0)/Pd(II) catalytic cycle and that the active catalysts are actually slowly formed palladium clusters [29]. Besides classical palladacydes, complexes with pincer-type ligands such as 2 [30] have become very popular in palladium catalysis [31]. 

A dinuclear Pt complex with chelating tris( -tolyl)phosphine and bridging chloro ligands has been converted into a neutral PPhs-coordinated complex 548 and then into cationic complexes containing phosphonium-substituted enolate ligands (549, Scheme 76). Reaction with phosphorus ylides produces 550 and 551. 

The methyl iridium dioxygen complex Ir(CH3)C0(02)[P(p-tolyl)3]2 reacts with added triphenylphosphine to produce triphenylphos-phine oxide (191). That this is a bimolecular reaction was demonstrated both by the complete absence of any oxidation of the tris(para-tolyl)-phosphine and by the lack of any substitution of the bound tris(para-tolyl)phosphine by triphenylphosphine. 

Arylation of a cyclopalladated complex derived from tri-(o-tolyl)-phosphine with phenylstannane J. Louie, J. F. Hartwig, Angew. Chem. Int. Ed. 1996, 35, 2359-2361. 

Furthermore, comparative studies with arylphosphine ligands in aqueous organic media demonstrated the superior activity of palladium tri(o-tolyl)-phosphine complexes [11] with an unusual combination of 10 mol% tributylamine with 1.5 equiv. of potassium carbonate in water [9]. The catalyst system was successfully applied to bromobenzene and even bromoanisole with water-insoluble styrene, yielding 86% product in 6 h with 1 mol% Pd (Eq. 6). 

Analogs of [Rh(NO)(PPhj)j] containing tri(p-tolyl)-, tri(p-fluorophenyl)- or tri -chlorophenyl)-phosphine have been prepared using iV-methyl-iV-nitrosotoluene-p-sulfonamide (equation 299), or from [Rh(NO)2Cl] . Only one of their reactions has been investigated (equation 300). The tritertiary phosphine (107) displaces all three PPh, ligands when allowed to react with [Rh(NO)(PPh3)3] to form the complex (133). The P NMR spectra of (133) and related complexes have been obtained. ... 

After impregnation of the polymeric support material with paUadium(II) tri-(o-tolyl)phosphine complexes the resulting catalyst material was tested in the Heck coupling of bromobenzene with butyl acrylate in DMF to yield 75% of -3-phenylacrylic... 

The application of ethylene in Heck reactions often shows different activities from other olefins, because of Wacker-type side reactions. It was found, however, that iodo- and acceptor-substituted bromoarenes are cleanly converted in aqueous media to the corresponding styrenes utilizing a palladiium-TPPMS complex [13]. Furthermore, high-purity 0- and p-vinyltoluenes were prepared in a dimethyl-formamide/water mixture with palladium tri(o-tolyl)phosphine complexes [14]. Here, the role of water may be the dissolution of the inorganic base (potassium carbonate) in the organic media. 

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