Furyl phosphines

The unsaturated c.vo-enol lactone 17 is obtained by the coupling of propargylic acetate with 4-pentynoic acid in the presence of KBr using tri(2-furyl)-phosphine (TFP) as a ligand. The reaction is explained by the oxypalladation of the triple bond of 4-pentynoic acid with the ailenyipailadium and the carbox-ylate as shown by 16, followed by reductive elimination to afford the lactone 17. The ( -alkene bond is formed because the oxypalladation is tnins addition[8]. [Pg.455]

T rimethylsilylethoxy-mcthyl)-2-(tri-n-butyl-stannyl)indole 3-Bromopropene, Pd,(dba)j, tri-(2-furyl)phosphine 93 [1]... [Pg.99]

In related work, 3-chloromethylcephems were coupled with tributyl(tnfluoro-vinyl)stannane catalyzed by tri(2-furyl)phosphine palladium(O) [7S, 19] (equation 13). [Pg.673]

Many procedures use Pb(OAc)2 or other Pd(II) salts as catalysts with the catalytic-ally active Pd(0) being generated in situ. The reactions are usually carried out in the presence of a phosphine ligand, with Lris-o-tolylphosphine being preferred in many cases. 7ra-(2-furyl)phosphine (tfp) is also used frequently. Several chelating diphosphines, shown below with their common abbreviations, are also effective. Phosphites are also good ligands.130... [Pg.716]

A tandem palladium catalyzed multi-component approach has been devised providing direct access to for instance trisubstituted thiophenes from the simple starting material 3-iodothiophene 41. In a representative experiment, the substrate 41 was converted to the product 42 by treatment with ethyl acrylate and iodobutane in the presence of a catalytic system consisting of Pd(OAc)2, tri(2-furyl)phosphine (TFP), norbomene, and a base. A mechanistic rationale accounting for this outcome was also proposed <06OL3939>. [Pg.117]

Exposure of the benzo[b]thiophene derivative 44 to a palladium catalyst in the presence of tri(2-furyl)phosphine (TFP) as the ligand led to the product 45, which incorporated two heterocyclic units from the starting material. The mechanistic aspects of this transformation were also discussed, which appears to involve palladacycle intermediates <06JA722>. [Pg.118]

Also a pyridazin-3(2//)-one, namely 4-bromo-5-methoxy-2-(4-trifluoromethylphenyl)pyridazin-3(2//)-one 169, has been successfully tackled (Equation 27) <2005JHC427>. In this case, the use of a tri(2-furyl)phosphine rather than a triphenylphosphine-based palladium catalyst was essential to achieve high yields. [Pg.53]

A variety of palladium(O) or palladium(ii)/phosphine systems have been used as catalyst precursors (Figure 9). Triphenylphosphine was usually the ligand of choice until Farina showed in 1991 that the use tri-(2-furyl)phosphine enhanced reaction rates. The positive effects of additives such as copper salts and diethylamine ... [Pg.13]

Essentially all triarylphosphines other than PPh3 are significantly more expensive than PPh3. Even so, some sterically and electronically modified monodentate triarylphosphines, such as tris(o-tolyl)phosphine (TTP)81a and tris(2-furyl)phosphine (TFP)81b, have exhibited catalytic reactivities that are clearly superior to those of PPh3 in many demanding cases of cross-coupling, such as a-alkenylation of a-haloenones82. [Pg.476]

Optimum conditions for the coupling of the alkenyl triflates 330 with the arylstannanes 331 have been studied. Ligandless Pd complexes such as Pd(dba)2 are most active in the reaction of the enol triflate. PI13P inhibits the reaction. NMP as a polar solvent gives the best results. The use of tri(2-furyl)phosphine and Ph As in the coupling of stannanes with the halides and triflates increases the rate of the transmetallation of the stannanes to Pd, which is thought to be the rate-... [Pg.70]

Hydroxypyridine may be allylated by Pd(0)-catalyzed nucleophilic attack of oxygen onto allene <2001T7965>. Reaction with 2 equiv of allene in THF in the presence of Pd(OAc)2 and tris-(2-furyl)phosphine gives 1,3-dienyl ether 105 in 34% yield (Equation 71). This process occurs in similar yield when performed on 3-hydroxyisoquinoline. [Pg.139]

Meanwhile charge the flame dried and argon flushed two-necked flask (25 mL) with Pd(dba)2 and tri(2-furyl)phosphine. Add THF (2 mL) and stir until the red colour is discharged (10 min) indicating the formation of the catalyst. [Pg.206]

Place in another flask Pd(dba)2 (86 mg, 0.15 mmol), tris(2-furyl)phosphine (70 mg, 0.3 mol), and dry dimethylformamide (5 mL). Stir the mixture until the dark solution turns clear. [Pg.222]

Farina has shown that the reaction of 129 with cinnamyl chloride in THF with Pd2(dba)3 and tri-(2-furyl)phosphine as precatalytic system, results in incomplete formation of the C-allylated 130a, the isomeric cinnamyl ether of 129 being also isolated (91JA9585). [Pg.99]

Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...