Dipalladium-tris

Pd2(dba)3 CHCI3, [tris(dibenzy 1 ideneacetone)dipalladium(chloroform)], HCO2H, 74-100% yield. ... 

B. (E)-4-(2-Phenylethenyl)benzonitrile (2). An oven-dried, 250-mL, three-necked, round-bottomed flask equipped with an argon inlet adapter, rubber septum, glass stopper, and a teflon-coated magnetic stir bar is cooled to room temperature under a flow of argon. The flask is charged successively with bis (tri-tert-butylphosphinc)palladium [(Pd(P(t-Bu)3)2] (0.238 g, 0.466 mmol, 1.5 mol% Pd) (Notes 1, 2), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (0.213 g, 0.233 mmol, 1.5 mol% Pd) (Note 3), and... 

The submitters used a two-necked, round-bottomed flask equipped with a magnetic stirbar, three-way stopcock connected to vacuum and a N2 source, and a solid addition tube. The addition tube was charged with methyl 4-iodobenzoate, tris(dibenzylideneacetone)dipalladium(0), and tri-o-tolylphosphine. After the zinc reagent was formed and the ice bath was removed, the solids contained in the addition tube were added in one portion by inverting the tube. 

Porco s pathway to complete the synthesis of (- )-kinamycin C (3) is shown in Scheme 3.8. The arylstannane 34 and the a-bromoenone 35 were efficiently coupled by a Stille reaction using tris(dibenzylideneacetone)dipalladium and triphenylarsine... 

The derivative 90 was obtained by condensation of the purpurin-18-A-hexylimide-17-propionic acid with aminolactose heptaacetate in the presence of benzotriazol-l-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate (BOP) followed by the deacetylation procedure. The lactose-photosensitiser conjugate linked by an ethylene moiety was also prepared by following a similar approach. The purpurin-18-methyl ester 81 was converted into /V-(3-iodobenzyl)/ /evo-purpurin-18-7V-hexylimide-17-propionic ester by hydrogenation over Pd/C followed by reaction with 3-iodo-benzylamine. Afterwards, the propargyllactose heptaacetate reacted with A-(3-iodobenzyl)rMeio-purpurin-18-A-hexylimide-l 7-propionic ester in the presence of tris(dibenzylidieneacetone)dipalladium(0) (Pd2-dba3) which, after deacetylation conditions, afforded the derivative 89 (Fig. 9).68... 

The 20-membered all-E tetraene macrolide system 58 was prepared by intramolecular cyclization of vinyl stannane 59 in the presence of tris(dibenzylideneacetone)dipalladium(0) (Pd2dba3) and triphenylarsine, as shown in equation 3354. E,E-Dienamines have been... 

Scheme 13. Synthetic ways to functionalized cyclopentadienones (i, CuCN, DMF ii, (CgH5)2NH, tris(dibenzylideneacetone)dipalladium (0), 2,2 -bis(diphenylphosphinol)-l,l -binaphthyl (rac.), CsCOj, toluene)...

Buchwald has shown that, in combination with palladium(II) acetate or Pd2(dba)3 [tris(dibenzylideneacetone)dipalladium], the Merrifield resin-bound electron-rich dialkylphosphinobiphenyl ligand (45) (Scheme 4.29) forms the active polymer-supported catalysts for amination and Suzuki reactions [121]. Inactivated aryl iodides, bromides, or even chlorides can be employed as substrates in these reactions. The catalyst derived from ligand (45) and a palladium source can be recycled for both amination and Suzuki reactions without addition of palladium. 

Cyclocarbonylation of o-iodophenols 503 with isocyanates or carbodiimides and carbon monoxide in the presence of a catalytic amount of a palladium catalyst (tris(dibenzylideneacetone)dipalladium(O) Pd2(DBA)3) and l,4-bis(di-phenylphosphino)butane (dppb) resulted in formation of l,3-benzoxazine-2,4-diones 504 or 2-imino-l,3-benzoxazin-4-ones 505 (Scheme 94). The product yields were dependent on the nature of the substrate, the catalyst, the solvent, the base, and the phosphine ligand. The reactions of o-iodophenols with unsymmetrical carbodiimides bearing an alkyl and an aryl substituent afforded 2-alkylimino-3-aryl-l,3-benzoxazin-4-ones 505 in a completely regioselective manner <1999JOC9194>. On the palladium-catalyzed cyclocarbonylation of o-iodoanilines with acyl chlorides and carbon monoxide, 2-substituted-4f/-3,l-benzoxazin-4-ones were obtained <19990L1619>. 

An N-heterocyclic carbene ligand, formed from l,3-bis-(2,4,6-trimethylphenyl)-3//-imidazol-l-ium chloride and cesium carbonate, with dipalladium tris(dibenzylideneacetone) gave excellent yields (93-96% yields) in the Suzuki coupling of 2-chloropurines and arylboronic acids in anhydrous dioxane <2001TL8751>. The combination of an imidazolium-carbene and nickel(O) bis(cyclooctadiene) formed a catalyst capable of insertion into the C-F bond of 6-fluoropurine nucleosides (Scheme 35) <20050L1149>. 

A 100-ml Schlenk flask was charged with the step 1 product (0.231 mmol), 5,5 -bis(5-bromo-2-thienyl)-4,4 -dihexyl-2,2 -bithiazole (0.231 mmol), tris(dibenzy-lideneacetone)dipalladium (0) (0.00231 mmol), triphenylphosphine (0.0162 mmol), and Aliquot 336 (0.0855 mmol). The flask was evacuated and refilled with argon... 

A mixture consisting of phenoxazine (54 mmol), sodium t-butoxide (77 mmol), tris(dibenzylidene acetone)dipalladium(0) (1.1 mmol), and tri(/-butyl)-phosphine (1.1 mmol) were dissolved in 250 ml of xylene and then heated to 80°C for 12 hours. Thereafter, the reaction mixture was cooled to ambient temperature, quenched with 200 ml of distilled water, and extracted with xylene/water, 1 1. 

PiMozOftPdiCijHU, Molybdenum, hexacar-bonylbis(r)5-cyclopentadienyl)-bis(tri-phenylphosphine)dipalladium di-, 26 348... 

Similarly, reaction of tris(dibenzylideneacetone)dipalladium with two equivalents of f-butylisocyanide per Pd atom, followed by addition of OFCOT, leads to an analogous ring-closed product 99a. Reaction of [Pd(PPh3)4] with OFCOT afforded the phosphine analogue 99b (174). No attempts have been made to probe any further chemistry of these molecules. 

Reaction of the bis(diphenylphosphino)methane (dppm) complex PdPt-(yi-dppm)2Cl2 (132) with carbonylate anions affords several tri- and tetranuclear clusters. Reactions are outlined in Scheme 7. Treatment of 132 with 2 mol equivalents of [Fe(CO)3(NO)] (796,797), [Co(CO)4] (196,198), or [Mn(CO)5] (196,197) results in the tetranuclear spiked triangular clusters 133,134, or 135. Crystal structures on the dipalladium analogues of 134 and 135 have been reported (797,799). Grossel et al. (136) and Braunstein et al. (200) have independently reported that reaction of 132 with 1 mol equivalent of [Fe(CO)4]2 at ambient temperatures leads to an inseparable 1 1 mixture... 

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