Dichloropalladium

Conventional synthetic schemes to produce 1,6-disubstituted products, e.g. reaction of a - with d -synthons, are largely unsuccessful. An exception is the following reaction, which provides a useful alternative when Michael type additions fail, e. g., at angular or other tertiary carbon atoms. In such cases the addition of allylsilanes catalyzed by titanium tetrachloride, the Sakurai reaction, is most appropriate (A. Hosomi, 1977). Isomerization of the double bond with bis(benzonitrile-N)dichloropalladium gives the y-double bond in excellent yield. Subsequent ozonolysis provides a pathway to 1,4-dicarbonyl compounds. Thus 1,6-, 1,5- and 1,4-difunctional compounds are accessible by this reaction. 

The employment of silver(i) complexes having a chiral carbene ligand L (Figure 19) and the empirical formula [AgBrL] has been reported for use as both carbene-transfer reagents to the corresponding dichloropalladium(n)... 

A recent publication by the group of Barbarella has disclosed the rapid preparation of poorly soluble unsubstituted and modified a-quinque- and sexithiophenes by the extensive use of bromination/iodination steps and microwave-assisted Suzuki and Sonogashira cross-couplings (Scheme 6.16) [42]. Suzuki reactions were either carried out under solvent-free conditions on a strongly basic potassium fluoride/ alumina support for the synthesis of soluble oligothiophenes, or in solution phase for the preparation of the rather insoluble a-quinque- and sexithiophenes. In both cases, 5 mol% of [l,l -bis(diphenylphosphino)ferrocene]dichloropalladium(II)... 

In a related approach from the same laboratory, the perfluorooctylsulfonyl tag was employed in a traceless strategy for the deoxygenation of phenols (Scheme 7.82) [94], These reactions were carried out in a toluene/acetone/water (4 4 1) solvent mixture, utilizing 5 equivalents of formic acid and potassium carbonate/[l,T-bis(diphe-nylphosphino)ferrocene]dichloropalladium(II) [Pd(dppf)Cl2] as the catalytic system. After 20 min of irradiation, the reaction mixture was subjected to fluorous solid-phase extraction (F-S PE) to afford the desired products in high yields. This new traceless fluorous tag has also been employed in the synthesis of pyrimidines and hydantoins. 

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 ... 

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)... 

Preparation of PdCl2(PhCN)2. The synthesis of bis(benzonitrile-dichloropalladium has been described previously.10 It can be performed in a manner analogous to that given in Section C for PtCl2(PhCN)2, affording yields of 95%, based on the starting PdCl2. 

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)... 

Desulfonation of ally lie sulfones.1 These sulfones undergo desulfonation with this borohydride in the presence of [l,3-bis(diphenylphosphine)propane]-dichloropalladium(II), PdCl2(dppp). This method is superior to use of NaBH4... 

Enol lactonization Bis(acetonitrile)dichloropalladium(II), 33 N-Phenylselenophthalimide, 245 Epoxidation of alkenes... 

Ethyl diphenylphosphinite, 131 Hexamethyldisilazane, 141 Thionyl chloride, 297 Zirconium(IV) acetylacetonate, 351 From other starting materials Acetohydroxamic acid, 2 Bis(benzonitrile)dichloropalladium(II), 34... 

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... 

E,4Z)-DIENOATES Alumina. D1ENONES Benzeneselcninic anhydride. Bis(acetonitrile)dichloropalladium(II). Perchloric acid. 

The Suzuki coupling reaction is a powerful tool for carbon-carbon bond formation in combinatorial library production.23 Many different reaction conditions and catalyst systems have been reported for the cross-coupling of aryl triflates and aromatic halides with boronic acids in solution. After some experimentation, we found that the Suzuki cleavage of the resin-bound perfluoroalkylsulfonates proceeded smoothly by using [l,l -bis (diphenylphosphino)ferrocene]dichloropalladium(II), triethylamine, and boronic acids in dimethylformamide at 80° within 8 h afforded the desired biaryl compounds in good yields.24 The desired products are easily isolated by a simple two-phase extraction process and purified by preparative TLC to give the biaryl compounds in high purity, as determined by HPLC, GC-MS, and LC-MS analysis. 

Carbonylative coupling of vinyl triflates with organotins (12, 470-471).3 The final step in a synthesis of the macrocyclic diterpene jatrophone (2) was effected by carbonylative coupling of a vinyl triflate with vinyltin catalyzed by bis(acetonitrile)-dichloropalladium. 

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