Tetrakis triphenylphosphine palladium

A detailed description of filtration under nitrogen has been given by W. L. Jolly, Inorganic Syntheses, 11, 117 (1968). 

Preparation of phosphine and phosphite complexes of palladium ) have been reported to result from reduction of palla-dium(II) complexes in the presence of the desired ligand.1 The products are generally formulated as PdL4 (where n = 0, 1), depending upon the nature and amount of the ligand used. A related complex, [Pd P(C6H5)3 2]re, has also been reported.6 

Although this preparation is similar in concept to these previous ones, advantage is gained in being able to obtain a high yield of [Pd P(C6H5)3 J in one step from palladium dichloride. 

A mixture of palladium dichloride (17.72 g., 0.10 mole), tri-phenylphosphine (131 g., 0.50 mole), and 1200 ml. of dimethyl sulfoxide is placed in a single-necked, 2-1., round-bottomed flask equipped with a magnetic stirring bar and a dual-outlet adapter (Note 1). A rubber septum and a vacuum-nitrogen 

A melting point determination (Note 2) on a sample in a sealed capillary tube under nitrogen gave a decomposition point of 116° (uncorrected). This compares with a similar determination (115°) performed on the product prepared by the method of Malatesta and Angoletta.1 Anal. Calcd. for C72H6oPdP4 C, 75.88 H, 5.25 P, 10.75. Found C, 75.3 H, 5.36 P, 10.7. 

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Tetrakis(triphenylphosphine) palladium [14221-01-3] M 1155.58, m 100-105"(dec). Yellow crystals from EtOH. It is stable in air only for a short time, and prolonged exposure turns its colour to orange. Store in an inert atmosphere below room temp in the dark. [7 Chem Soc 1186 1957.]... 

A variety of catalysts, solvents and amines as base can be employed for the Sonogashira reaction. Typical conditions are, e.g. tetrakis(triphenylphosphine)palladium(0)... 

A synthetically useful virtue of enol triflates is that they are amenable to palladium-catalyzed carbon-carbon bond-forming reactions under mild conditions. When a solution of enol triflate 21 and tetrakis(triphenylphosphine)palladium(o) in benzene is treated with a mixture of terminal alkyne 17, n-propylamine, and cuprous iodide,17 intermediate 22 is formed in 76-84% yield. Although a partial hydrogenation of the alkyne in 22 could conceivably secure the formation of the cis C1-C2 olefin, a chemoselective hydrobora-tion/protonation sequence was found to be a much more reliable and suitable alternative. Thus, sequential hydroboration of the alkyne 22 with dicyclohexylborane, protonolysis, oxidative workup, and hydrolysis of the oxabicyclo[2.2.2]octyl ester protecting group gives dienic carboxylic acid 15 in a yield of 86% from 22. 

Allylic acetates of either geranyl acetate or neryl acetate reacted with the sodium salt of methyl phenylsulfonyl acetate in the presence of tetrakis(triphenylphosphine palladium) affording the corresponding olefin, with a retained geometry at the primary carbon... 

Tetraalkylammonium hydroxides, 405 Tetrabutoxytitanium, 70 Tetrabutyltin, 68 Tetraethoxysilane (TEOS), 348 Tetrahydrofuran (THF), 348 Tetrakis(triphenylphosphine)palladium(0), 486... 

Benzy 1-6-chloropurine reacts with tetrakis(triphenylphosphine)palladium in DCE to give, not only the 6-purinylpalladium(Il) complex 102, but a dinuclear complex 103. Using Stille coupling (RSnBus) only the 6-substituted purine is obtained <96ACS462>. 

In 1988, Linstrumelle and Huynh used an all-palladium route to construct PAM 4 [21]. Reaction of 1,2-dibromobenzene with 2-methyl-3-butyn-2-ol in triethylamine at 60 °C afforded the monosubstituted product in 63 % yield along with 3% of the disubstituted material (Scheme 6). Alcohol 15 was then treated with aqueous sodium hydroxide and tetrakis(triphenylphosphine)palladium-copper(I) iodide catalysts under phase-transfer conditions, generating the terminal phenylacetylene in situ, which cyclotrimerized in 36% yield. Although there was no mention of the formation of higher cyclooligomers, it is likely that this reaction did produce these larger species, as is typically seen in Stephens-Castro coupling reactions [22]. 

The Suzuki-Miyaura synthesis is one of the most commonly used methods for the formation of carbon-to-carbon bonds [7]. As a palladium catalyst typically tetrakis(triphenylphosphine)palladium(0) has been used, giving yields of44—78%. Recently, Suzuki coupling between aryl halides and phenylboronic acid with efficient catalysis by palladacycles was reported to give yields of 83%. 

Bromobenzaldehyde and 4-fluorophenylboronic acid were coupled in DMF using tetrakis(triphenylphosphine)palladium(0) as catalyst [85] (see a more extended description in [42]). 

The synthesis of the second Stille coupling partner 34 was efficiently achieved in three steps. First, 2-bromojuglone (36) [28] was protected as its methoxymethyl ether (46, Scheme 3.7). The quinone was reduced using sodium thiosulfate, and the resulting hydroquinone was protected with methoxymethyl chloride to afford the arene 47. Finally, stannylation using tetrakis-(triphenylphosphine)palladium and hexabutylditin [29] afforded the cross-coupling partner 34 in high yield. 

C. 4-(3-Cyclohexenyl)-2-phenylthio-1-butene. To the above solution of the borane derivative, 0.809 g (0.700 mmol) of tetrakis(triphenylphosphine)palladium(0) (Note 9), 1.47 g (5.60 mmol) of triphenylphosphine (Note 10), 35 mL of 3 M potassium phosphate in water (Note 11), and finally 15.1 g (70.0 mmol) of 1-bromo-1-phenylthioethene are added and the resulting mixture is heated at reflux for 3 hr with stirring. The light brown solution is cooled to room temperature and treated with 6.4 g... 

Tetrakis(triphenylphosphine)palladium(0) Palladium, tetrakis(triphenylphosphine)-(8) Palladium, tetrakis(triphenylphosphine)-, (T-4)- (9) (14221-01-3) Triphenylphosphine Phosphine, thphenyl- (8,9) (603-35-0)... 

Bromobenzene (0.63 g, 4.0 mmol) was added to a stirred mixture of diethyl phosphite (0.61 g, 4.4. mmol), triethylamine (0.44 g, 4.4 mmol), and tetrakis(triphenylphosphine)palladium (0.23 g, 0.2 mmol) under a nitrogen atmosphere. The mixture was stirred for... 

One of the earliest syntheses of lavendamycin methyl ester, however, did not employ either the Pictet-Spengler or the Bischler-Napieralski reactions for construction of the /J-carboline ring system. Instead, a palladium-promoted ring closure of aryl pyridine 36 (Fig. 12) was used to prepare /1-carboline 37 by Boger and coworkers [35]. Unfortunately, stoichiometric palladium was found to be necessary, in this case 1.5 equivalents of the tetrakis(triphenylphosphine)palladium(0) being used. Friedlander condensation with aldehyde 38 in the presence of benzyltrimethylammonium hydrox-... 

Diynes.1 In the presence of tetrakis(triphenylphosphine)palladium(0), (Z)-l,2-dichloroethylene couples with a terminal alkyne to form a (Z)-chloroenyne, which undergoes anti-elimination of HC1 to give a 1,3-diyne on treatment with Bu4NF. 

Hydrosilanes-Tetrakis(triphenylphosphine)palladium(0)-Zinc chloride... 

In another reduction, the propargylic phosphate 64 is reduced with samarium(II) iodide in the presence of tetrakis(triphenylphosphine)palladium and tert-butanol as a proton source the allene 65 is produced almost exclusively, <1% of the isomeric alkyne 66 being present in the product mixture [19]. 

Various intermolecular coupling reactions involving acetylene hydrocarbons have been reported to lead to vinylallenes. For example, 1-phenylpropyne (93), after activation with Hg(II) chloride, is first metalated by butyllithium treatment, then trans-metalated with zinc bromide and finally coupled with 1-iodo-l-phenylethene (94) in the presence of tetrakis(triphenylphosphine)palladium to provide the diphenylvinyl-allene 95 in moderate yield (Scheme 5.12) [31]. 

The procedure described here incorporates a number of modifications to the Suzuki coupling that result in a sound, efficient and scaleable means of synthesizing biaryls. First, the catalytic use of palladium acetate and triphenylphosphine to generate palladium(O) eliminates the need for the expensive air and light sensitive tetrakis(triphenylphosphine)palladium(0). No purification of reagents is necessary, no special apparatus is required, and rigorous exclusion of air from the reaction mixture is not necessary. Furthermore, homo-coupled products are not present in significant levels (as determined by 500 MHz 1H NMR). 

The sodium salt of 18 condenses with allylic acetates (E)-R1 CH=CH—CHR2OAc (R1 = Ph or C7H15 R2 = Me or C7H15) in THF in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium(0) to give doubly protected allylic amines (equation 17)49. 

Substitution reactions of allylic nitro compounds often lead to rearranged products, as in palladium(0)-catalysed aminations and alkylations. Thus treatment of the nitro ester 419 with piperidine in the presence of tetrakis(triphenylphosphine)palladium yields a mixture of the unrearranged and rearranged amines 420 (R = piperidin-l-yl) and 421... 

Palladium-catalyzed, Allylic Amination. Allylic substitution of mono-saccharidic hex-2-enopyranoside 4-acetates with secondary amines in the presence of tetrakis (triphenylphosphine)palladium(O) liad led to a large variety of 4-aminated 2-enosides, with retention of configuration (56-58). The method was applied to the disaccaridic enoside 1 to give, with benzylmethylamine or dibenzylamine, the 4-amino sugar derivatives g in yields of 92 and 67% (46). Studies concerning hydrox-ylation of t)ie double bond and subsequent deprotection are incomplete. 

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