Reaction with palladium

Methylphenyl)benzothiazole (80IC762) and 2-benzylbenzothiazole (95ICA(239)125) can be cyclopalladated. In the latter case, cylopalladation occurs upon reaction with palladium(II) acetate and gives the product 80. With lithium chloride, sodium bromide, or sodium iodide, a series of three products of substitution of the acetate group 81 (X = C1, Br, I) results. Pyridine, 2- and 3-methylpyridine, 2,6- and 3,5-dimethylpyridine cause the transformation of the chelate complexes 81 (X = C1, Br, I) and formation of the mononuclear products 82 (R = z= R" = = R = H, X = Cl, Br, I ... 

Scheme 6/1.58. Domino reaction with palladium on charcoal as catalyst.

Several reports covering carbonylation and other aspects of homogeneous catalysis include the hydroxycarbonylation reaction with palladium systems.310,311,629 A review summarizing the results and findings about the mechanism has been published.630 The carbonylation of vinyl... 

The use of 1,6-diene systems usually does not result in cyclization reactions with palladium ) salts. For example, with 1,6-heptadiene a /i-elimination takes place from the cqjr-intermediate to give diene 22 as the major product (equation 10)27. However, more recently Trost and Burgess21 have shown that with a 4,4-bis(phenylsulfonyl) derivative of 1,6-heptadiene (23) an insertion takes place to give a 5-membered ring product (24, equation 11). The final step of the latter reaction is oxidative cleavage of the palladium-carbon bond by CuCl2 to produce a carbon-chlorine bond. 

Wacker cyclization has proved to be one of the most versatile methods for functionalization of olefins.58,59 However, asymmetric oxidative reaction with palladium(II) species has received only scant attention. Using chiral ligand 1,1 -binaphthyl-2,2 -bis(oxazoline)-coordinated Pd(II) as the catalyst, high enantioselectivity (up to 97% ee) has been attained in the Wacker-type cyclization of o-alkylphenols (66a-f) (Scheme 8-24). 

The zinc reagents described above have shown extensive utility in coupling reactions with palladium catalysis. For example, coupling with heterocyclic iodides provides the corresponding fluorinated vinyl derivatives, as illustrated in equations 9-11. 

Allyl esters, carbonates, and carbamates readily undergo C-O bond cleavage upon reaction with palladium(O) to yield allyl palladium(II) complexes. These complexes are electrophilic and can react with nucleophiles to form products of allylic nucleophilic substitution. Linkers based on this reaction have been designed, which are cleavable by treatment with catalytic amounts of palladium complexes [165,166], For the immobilization of carboxylic acids, support-bound allyl alcohols have proven suitable (Figure 3.12, Table 3.7). 

Ligand-exchange reactions with palladium-calcein.196... 

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