Yu. V. Gulevich

Reactions of organometallic compounds catalyzed by transition-metal complexes. XI: The palladium-catalyzed reaction of acyl chlorides with Et6Sn2 as a route to symmetrical ketones and α-diketones

Abstract The reaction of aroyl chlorides (ArCOCl) with Et6Sn2 gives symmetrical ketones (Ar2CO) or α-diketones ((ArCO)2), depending on the nature of the palladium catalyst and the reaction conditions. The synthesis of α-diketones from AlkCOCl and HetCOCl has been performed for Alk = n-C7H15 and Het = 2-C4H3O (furyl). The palladium-catalyzed carbonylation of aryl iodides in the presence of Et6Sn2 may serve as another route to symmetrical α-diketones. Such a possibility has been demonstrated for the preparation of 4,4′-dimethoxybenzil from 4-iodoanisole, carbon monoxide, and Et6Sn2.

Palladium-catalyzed synthesis of aromatic acid derivatives by carbonylation of aryl iodides and Alk3SnNu (Nu = MeO, Et2N, PhS, EtS)

Abstract Carbonylation of the ArI/Alk 3 SnNu system (Nu=MeO, Et 2 N), leading to esters and amides of substituted benzoic acids, occurs readily in the presence of phosphinepalladium complexes. When Nu = PhS and EtS either a cross-coupling product (Ar = p -NO 2 C 6 H 4 ) or a carbonylation product (Ar = Ph) is formed predominantly, depending on the nature of ArI. Stoichiometric reactions of ArPdI(PPh 3 ) 2 with carbon monoxide, resulting in acylpalladium complexes, and reactions of ArCOPdI(PPh 3 ) 2 with Alk 3 SnNu have been studied. Some mechanistic aspects are discussed.

A model for CO insertion in transition metal complexes

A theoretical model recently developed for describing reactions catalysed by transition metal complexes is applied to CO insertion in RML, complexes (where M is a transition metal, R is aryl, alkyl, or another u-bonded ligand, and L stands for ancillary ligands). The effect of the migrating group R, the metal M, and the number of ancillaty ligands L on the insertion step is studied. The mechanism of the double carbonylation reactions of organic halides, catalysed by transition metal complexes, is analysed in the framework of the proposed model.

Synthesis of hexaalkyl(aryl)distannanes and their reaction with organic halides under conditions of catalysis by palladium complexes

Conclusions1.A convenient method has been developed for the synthesis of hexaalkyl- and hexaaryl-distannanes by the dehydrogenation of R3SnH in the presence of catalytic amounts of Pd complexes.2.The reaction of hexaalkyldistannanes with organic halides has been studied under conditions of catalysis with Pd complexes. A method has been developed for the synthesis of aryltrialkylstannanes with active electron-accepting substituents in the aromatic ring.

Reaction of 2-vinylpyridine and 2-(1-methoxyvinyl)pyridine with acrylic acid derivatives

The regiospecificity of the reaction of 2-vinylpyridine and 2-(1-methoxyvinyl)-pyridine with acrylonitrile and methyl acrylate was predicted on the basis of MO perturbation theory and was confirmed experimentally. The regioisomeric compositions of the reaction mixtures were studied by means of chromatographic mass spectrometry.