Olga A. Maloshitskaya

Palladium-Catalyzed Amination of Dichloroquinolines with Adamantane-Containing Amines

Pd-catalyzed amination of isomeric 2,6-, 2,8-, 4,8- and 4,7-dichloroquinolines was studied using adamantane-containing amines in which substituents at the nitrogen atom differ in bulkiness. The selectivity of the amination of 2,6-dichloroquinoline was very low, substantially better results were obtained with 2,8-dichloroquinoline, and 4,8- and 4,7-dichloroquinolines provided the best yields of the amination products. Diamination of 4,8- and 4,7-dichloroquinolines was carried out with two amines which differ strongly in the bulkiness of the alkyl group. In the majority of cases BINAP ligand was successfully applied, however, it had to be replaced with DavePhos in certain reactions when using the most sterically hindered amine as well as for the diamination reactions.

Arylation of adamantanamines: VII. Copper(I)-catalyzed N-heteroarylation of adamantane-containing amines with halopyridines

Copper(I)-catalyzed N-heteroarylation of a wide series of adamantane-containing amines with 2-bromo- and 2- and 3-iodopyridines was studied. The corresponding N-pyridyl derivatives were formed in all cases, but iodopyridines were considerably more reactive. The best results were obtained with the catalytic system CuI-2-(2-methyl-1-oxopropyl)cyclohexanone-DMF which ensured up to 90% yield of the target products. The yield of N-pyridyl derivatives also depended on the steric environment of the amino group in the initial adamantane-containing amine. The yield of the heteroarylation products can be considerably increased using excess iodopyridine. The reaction of 2-(adamantan-1-yl)ethanamine with 2,6-dibromopyridine successfully afforded the corresponding diamine, and N,N′-dipyridyl derivatives were obtained in high yields from 2,2′-(adamantane-1,3-diyl)diethanamine.

The first solid phase synthesis of pincer palladium complexes

Both dimeric μ-chlorine bridged and monomeric bidentate Pd(II) complexes with SCN hybrid pincer-type ligands, bearing thiophosphoryl group and imine moiety of the benzothiazole ring as coordination arms, formed in the reaction with (PhCN)(2)PdCl(2) under kinetic control (20 °C, dichloromethane solution) were readily converted into the corresponding SCN pincer complexes via solid phase synthesis (neat, 200 °C, 15 min). The synthesis of pincer complexes can be performed also by heating (200 °C, 5 min) of a homogeneous mixture of the initial reactants, namely, the ligand and (PhCN)(2)PdCl(2), obtained by manual grinding in a mortar. The efficacy of solid phase approaches is comparable with the analogous synthesis in solutions under severe conditions.

Arylation of adamantanamines: V. Palladium-catalyzed amination of isomeric chloroquinolines with diamines of the adamantane series

Palladium-catalyzed arylation of diamines of the adamantane series with isomeric 2-, 4-, and 6-chloroquinoline was studied, and optimal conditions for the synthesis of the corresponding N,N′-diaryl derivatives were found. N,N-Diarylation products of primary amino groups in the diamines bearing 2-aminoethyl and 4-aminophenyl substituents were readily formed.

Arylation of adamantanamines: IV. Palladium-catalyzed arylation of amines of adamantane series with isomeric chloroquinolines

Palladium-catalyzed arylation of diverse amines of the adamantane series with isomeric chloroquinolines was investigated. The 2-chloroquinoline is the most reactive, however the best yields of the N-arylation products are most frequently obtained in the reaction with the less reactive 6-chloroquinoline. The applicability of the reaction is limited by the size of the substituent at the amino group. In some instances the noncatalytic amination of chloroquinolines was possible.

Palladium-catalyzed amination in the synthesis of aza- and diazacrown trismacrocyclic compounds

Palladium-catalyzed C-N-cross-coupling of N,N′-bis(bromobenzyl) diazacrown compounds with two equivalents of 1-aza-15-crown-5 and 1-aza-18-crown-6 ethers furnished trismacrocyclic compounds with isolated macrocycles. Macrotricyclic cryptands were obtained when diazacrown ethers were used as N-components.

Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines with aryl iodides

Summary The Cu(I)-catalyzed N,N’-diarylation of natural diamines and polyamines such as putrescine, cadaverine, spermine, spermidine and their homologues is described. Aryl iodides bearing electron-donating and electron-withdrawing groups have been employed in the study. The CuI/2-(isobutyryl)cyclohexanone/DMF catalytic system has found to be more efficient in the diarylation of diamines and spermine while the CuI/L-proline/EtCN system proved to be preferable for the diarylation of other tri- and tetraamines like spermidine, norspermidine and norspermine.

CuI-catalyzed N,N’-diarylation of diamines of adamantane series

A copper(I) complex-catalyzed N,N’-diarylation of diamines based on 1,3-disubstituted adamantane, using aryl iodides bearing electron-donating and electron-withdrawing substituents, was studied. In the case of 2,2’-(adamantane-1,3-diyl)ethanediamine, the optimal catalyst system is CuI—2-(isobutyryl)cyclohexanone—Cs2CO3—DMF. The highest yield of diarylation product was reached in the case of 4-methoxyiodobenzene (79%). In the case of more spatially hindered adamantane-1,3-diyldimethanamine, 1,1’-binaphthalene-2,2’-diol (BINOL) should be used, with the highest yield of the target product (84%) being reached in the reaction with iodobenzene.

Cyclization of 2-acyl- and 2-thioacylamino- benzylcyclopropanes in the gas phase and solution

Mass spectrometry proved itself to be a powerful tool to predict the directions and yields of mono-molecular reactions of organic compounds. Electron ionization (EI) and electrospray ionization (ESI) were used to study possible transformations of N-(ortho-cyclopropylmethylphenyl)arylamides I and N-(ortho-cyclopropylmethylphenyl)arylthioamides II as well as their para-isomers III and IV in a mass spectrometer and to predict directions and yields of their acid catalyzed cyclization reactions. Several five–eight-membered heterocycles were proposed as possible products of intramolecular transformations of compounds I and II. Reactions of compounds I and II in sulfuric acid solutions were carried out and the results obtained were compared with mass spectrometric data. Surprisingly, EI of the studied compounds mimics their solution reactions better than ESI.

Arylation of adamantanamines: VIII. Optimization of the catalytic system for copper-catalyzed arylation of adamantane-containing amines

Arylation of adamantane-containing amines with iodobenzene in the presence of copper(I) and copper(II) compounds and various N,N-, N,O- and O,O-bidentate ligands was studied. The best results were obtained using the catalytic system CuI–rac-BINOL [1,1′-bi(naphthalen-2-ol)] (10/20 mol %). Reactions with iodobenzene derivatives containing electron-donor and electron-withdrawing substituents in the para position to the iodine atom were carried out under the optimal conditions.