Dichloropalladium palladium

Bis(diphenylphosphino)ferrocene]dichloropalladium Palladium, [1,1-bis(diphenylphosphino)ferrocene-P,P ]dichloro- (10) (72287-26-4) Bis(benzonitrile)dichloropalladium(ll) Palladium, bis(benzonitrile)dichloro- (8, 9) (14220-64-5)... 

Synonyms palladium (II) chloride palladous chloride palladium dichloride dichloropalladium palladium(ous) chloride... 

Davies (69) has carried out a series of isomerization experiments in a medium consisting of acetic acid, palladium(II) chloride, and sodium chloride, the latter in a 1 1 mole ratio. In this system sodium 1,2,3,4-/ii,/x -dichloropalladium(II) was assumed to be present ... 

Dihydro-2H-pyran 2H-Pyran, 3,4-dihydro- (8,9) (110-87-2) tert-Butyllithium Lithium, tert-butyl- (8) Lithium, (1,1-dimethylethyl)- (9) (594-19-4) Palladium(ll) chloride bisacetonitrile Aldrich Bis(acetonitrile)dichloropalladium(ll) Palladium, bis(acetonitrile)dichloro- (8,9) (14592-56-4)... 

Osmium tetroxide-N-Methyl-morpholine N-oxide, 222 Osmium tetroxide-Trimethylamine N-oxide-Pyridine, 223 Palladium Compounds Benzylchlorobis(triphenylphosphine)-palladium(II), 30 Bis (ace tonitrile) chloronitropalla-dium(II)-Copper(II) chloride, 33 Bis(acetonitrile)dichloropalladium(II), 33, 211, 236... 

During their work on the arylation of aromatic compounds by substitution, Fujiwara, et al. observed biaryl formation when aromatic compounds were placed in the presence of olefin-palladium complexes and silver nitrate.80 Developing this reaction as a method for biphenyl synthesis, these authors showed that the more stable the olefin-palladium complex was, the lower the yield. Ethylene dichloropalladium proved to be the best choice, when used with silver nitrate. However, the reaction required stoichiometric amounts of both catalysts (Scheme 10.47). Benzene derivatives substituted by electron-donating or -withdrawing groups reacted as well, but a mixture of regioisomers was produced, except for nitrobenzene, which only gave m,m -dinitrobiphenyl. 

Phenyl triphenylgermyl or triphenylstannyl tellurium transferred the benzenetellurolate group to palladium in a reaction with bis[benzonitrile]dichloropalladium(II)1. 

When benzoyl aryl tellurium and bis[benzonitrile]dichloropalladium were stirred in chloroform, polymeric bis[aryllellurolato]palladium compounds were isolated. The benzoyl group was cleaved from the tellurium atoms during these reactions. 

Dichloro(ethylenediamine)palladium(II) is formed as yellow needles. (2,2 -Bipyridine)dichloropalladium(II) is produced as a light yellow microcrystalline solid that can be obtained as larger crystals by careful recrystallization from hot, dilute HC1 solutions. Both compounds are insoluble in cold water, but are moderately soluble in hot water. The compounds dissolve in 1 M sodium hydroxide with reaction. In general the compounds are not soluble in organic solvents however, both complexes can be dissolved in dimethyl sulfoxide and A>Y-di met hy If or mami de. 

NAZAROV CYCLIZATION Aluminum chloride. Benzylchlorobis(triphenylphos-phine)palladium. Bis(acetonitrile)-dichloropalladium(II). Boron trifluoride etherate. Tetrakis(triphenyl-phosphine)paIladium. 

An X-ray analysis (26,32) of the yellow, monomeric (norbornadiene)-dichloropalladium(II) (1, 6) has shown the diene molecule chelated to palladium with both double bonds perpendicular to the coordination plane. The distance from the Pd atom to the trigonal carbons is about 2.16 A and the angle subtended at Pd(II) by the coordinate bonds is 71.8°, The bond lengths within the norbornadiene molecule appear to be changed very little by coordination. 

Rearrangement of cis,reaction with bis(benzonitrile)dichloropalladium(II) in benzene has also been reported (581). The product is (m-l,2-divinylcyclohexane)dichloro-palladium(II), a monomeric complex decomposing above 123°C. The... 

Fig. 4 Additional reactions and cross-couplings that are commonly used to synthesize fluorene co-oligomers, where Pd(OAc)2 is palladium(II) acetate and PdCblPPhs) is bis(triphenylphosphino) dichloropalladium(II)...

The reaction of 13x with bis(benzonitrile)dichloropalladium(II) [Bn2PdCl2[ and monochloro(l,5-cyclooctadiene)monomethylpalladium(ll) [(COD)PdCIMe] yielded the corresponding palladium(II) complexes 14x and 15x (Fig. 2.16). Upon slow evaporation of an acetonitrile solution, 14 c and 14 d gave crystals that were suitable for structure determination via single crystal X-ray diffraction (Fig. 2.17). Compound 14 b was crystallized by slow diffusion of pentane into a solution of 14b in tetrachloroethane. 

When phosphane-free palladium catalysts, such as bis(dibenzylideneacetone)palladium, bis(jy4-cycloocta-l,5-diene)palladium, tris(norbornene)palladium or a catalyst generated in situ from bis(acetylacetonato)palladium and ethoxydiethylaluminum, are used with 3,3-dimethylcyclopropene, dimer 17 is obtained as the major product (76% when R1 = R2 = Me), along with three tetrameric products in a combined yield of 12.3%. Complexes such as bis(7r-allyl)pal-ladium and bis(acetonitrile)dichloropalladium also act as catalysts but mainly lead to higher oligomers.42 Other 3,3-dialkylcyclopropenes react in the same manner.36 ... 

Metal-catalysed cyclization is an increasingly important method of synthesis (reviews [B-4I, 2998, 3069, 3501, 3505 ). Bis(acetonitrile)dichloropalladium promotes cyclization of an alkynyl carbamate with epoxypropane and a vinyl chloride [3438] an alkynylaniline is converted into an indole by heating with a palladium chloride-triphenylphosphine catalyst [3631]. Mercury(II) acetate is an effective promotor of the cyclization of the alkenylaniline (37.2) to a reduced carbazole [3861]. 

Palladium(II)-induced Claisen rearrangements can be performed under mild reaction conditions with high E selectivity. For example, bis(acetonitrile)dichloropalladium(II) [Pd-Cl2(CH3CN)2] is an effective catalyst for the rearrangement of allyl 1-phenylvinyl ethers135. 

J23-22-Acetoxycholcstcrol derivatives can be converted stereoselectively with bis(aceto-nitrile)dichloropalladium(II) as a catalyst to 24-hydroxycholesterol derivatives435. The (225,23 )- and (225,23Z)-diastereomers react more rapidly than the (22i ,23 >isomer, and the (22i ,23Z)-compound does not rearrange under the reaction conditions. The difference in the reactivity is attributed to the different conformations of the side chains of the 22-hydroxy-cholesterol derivatives, as the coordination of the palladium complex with the 7t-electrons of the double bond from the side opposite the acetoxy group is sterically hindered in the less reactive derivative. 

The palladium(II)-catalyzed allyltrichloroacetimidate rearrangement can be performed under mild reaction conditions at room temperature with complete chirality transfer. Thus, reaction of O-protected optically active allyltricbloracctimidates 6 in the presence of 10mol% of bis(bcnzonilrile)dichloropalladium(II) in toluene provides a method for the synthesis of (E)-/i,y-unsaturated 2-amino acids365. Thermal rearrangements of 6 do not proceed with complete chirality transfer. 

CycUzation. The last step in a total synthesis of ibogamine (2) involved cyclization of 1 with bis(acetonitrile)dichloropalladium(II) assisted by silver tetrafiuoroborate and triethylamine. Work-up included reduction of an intermediate palladium species with NaBH. The alkaloid was obtained in 40-45% yield. This cyclization is related to the olefin arylation of Heck, catalyzed with phenylpalladium acetate, CeHsPdOCOCHa. ... 

An interesting application of the chiral cyclopalladated complexes is palladium-promoted asymmetric Diels-Alder reactions of l-phenyl-3,4-dimethylphosphole (Scheme 4). In the original report on the Diels-Alder reaction of the phosphole reported by Nelson and co-workers, the dichloropalladium species was employed as a promoter.f In 1994, Leung showed that a chiral cyclopalladated complex was capable of promoting the Diels-Alder reaction. In this reaction, the chiral palladacycle worked as a chiral auxihary and showed almost perfect diastereoselectivity. It has been revealed that simultaneous precoordination of a diene and a dienophile to the palladium center is essential for the reaction. Thus, both dienes and dienophiles should possess Lewis basic functionahty. The diene l-phenyl-3,4-dimethylphosphole has been the only substrate examined so far, while a variety of dienophiles, such as vinylphosphine, vinyl-sulfoxide, vinylsulfide, acrylamide, vinylarsine, vinylpyridine, vinyl-pyrrole, or methylenequinuchdinone, have successfully been applied to this asymmetric Diels-Alder reaction. 

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