R. V. Kunakova

New approach to the synthesis of alkylthioamides using catalysts containing cobalt complexes

Conclusions1.It is shown that alkylthioamides can be synthesized in high yields by the reaction of elemental sulfur with alkylacetylenes in DMF solution, catalyzed by cobalt complexes.2.In the presence of phosphine, cyclooctasulfane and DMF complexes of cobalt are able to isomerize the inner triple bond in alkynes into the terminal position.

Gan original method for the preparation of sulfides and disulfides involving cobalt complexes

Linear and cyclic sulfides and disulfides have been prepared by the combined reaction of elemental sulfur with alkylacetylenes and alkyl halides catalyzed by low-valence cobalt complexes. Heating equimolar amounts of cyclooctasulfane (

Telomerization of cyclic and linear glycols with butadiene, catalyzed by phosphine complexes of palladium

8) , l-hexyne and butyl chloride in DMF solution of 1:2:4 Co(acac)2-Ph3P-EtaAl at 130~ for 6 h gave a mixture of (l-methyl)-iZpentenyl butyl sulfide (I), (l-methyl)-iE-pentenyl butyl sulfide(II), 2,5-dibutylthiophene(III), 3,6-dibutyl-l,2-dithiacyclo-3,5-hexadiene (IV), dibutyl disulfide (V), and dibutyl trisulfide (VI) in 23:19:3:35:15:5 ratio with 82% overall yield.

Metal complex-catalyzed synthesis of dihydrothiapyrans from dialkyl sulfoxides and 1,3-dienes

Conclusions1.The telomerization of butadiene with cyclic 1,2-glycols and unsaturated linear 1,4- and 1,8-diols catalyzed by low-valency palladium complexes leads to the corresponding 2,7-octadienyl and 1-vinyl 5-hexenyl ethers in high yield.2.Under the influence of low-valency palladium complexes cyclic 2,7-octadienyl ethers are isomerized to 1-vinyl 5-hexenyl ethers.

Synthesis of higher unsaturated sulfides using palladium complexes

A preparative method has been developed for the synthesis of dihydrothiapyrans from dialkyl sulfoxides and 1,3-dienes, catalyzed by palladium and nickel complexes. The scope of this reaction has been assessed, and a mechanism proposed, using 1,3-dienes and sulfoxides of varying structure.

Mechanism of telomerization of 1,3-dienes with sulfinic acids, catalyzed by palladium complexes

Conclusions1.The telomerization of α-toluenethiol or thiophenol with butadiene has been accomplished using low-valence palladium complex catalysts to give higher homolog 1,6- and 2,6-octadienyl sulfides.2.The feasibility of Ni, Co, Fe, Cu, and Mn complexes as catalysts for the telomerization of butadiene with a-toluenethiol has also been demonstrated.

Novel reaction for the preparation of alkyl vinyl sulfides using metal complex catalysts

The probable telomerization mechanism was studied by IR spectroscopy, according to which the reaction of 1,3-dienes with sulfinic acids proceeds through a stage of formation of S-sulfinate complexes of palladium, which bring about the formation of molecules of unsaturated sulfones.

Activation of the S-S bond in diphenyl disulfide by nickel complexes and its reaction with butadiene

The feasibility of the one- step synthesis of mixtures of Z- and E- alkenyl alkyl sulfides via the reaction of elemental sulfur with terminal and disubstituted alkynes and alkyl halides has been demonstrated in the presence of low- valent Ni, Co, Pd, and Fe complexes. The effects of structure in the starting alkynes and alkyl halides have been investigated, along with process conditions and their effect on the composition and yields of reaction products.

Synthesis of cyclic 1,4-disulfides and alkylthiophenes by catalytic thiacyclization of acetylenes with sulfur

We are the first to demonstrate the possibility of obtaining unsaturated monoand disulfides (I)-(VI) by the reaction of diphenyl disulfide with butadiene taken in 1:20 ratio in DMF. The reaction is carried out at 150~ for 20 h in the presence of Ni(acac) 2Ph2PCH2CH2PPh 2 as catalyst (Ni:P = 1:2). The introduction of small molecules such as CO= and NH 3 into the catalytic system is a necessary condition for obtaining sulfides (I)-(VI) in yields of about 80% (Ni:CO2:NH 3 = 1:500:300). In the absence of such small molecules, the yield of (I)-(Vl) does not exceed 20%. Products (I)-(IV) were isolated as pure compounds by distillation on a Widmer column, while (V) and (VI) were detected only by mass spectrometry due to their low content in the reaction mixture. Under optimal conditions, the (I):(II):(III):(IV):(V):(VI) ratio was 30:32:20:15:2:1.

Reaction of 3-sulfolene with 1,3-dienes, catalyzed by palladium complexes

Conclusions1.The thiacyclization of mono- and disubstituted acetylenes with sulfur, leading to the production of dialkyl-1,4-dithiacyclohexa-2,5-dienes and thiophenes with high yield and catalyzed by the Co(acac)2-AlEt3 system in the presence of various ligands, is characterized.2.The path of thiacyclization depends on the structure of the starting acetylene and the nature of the catalyst.