scholarly journals Recent Advances in the Synthesis of Sulfides, Sulfoxides and Sulfones via C-S Bond Construction from Non-Halide Substrates

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1339
Author(s):  
Rui Zhang ◽  
Huaiwei Ding ◽  
Xiangling Pu ◽  
Zhiping Qian ◽  
Yan Xiao
Keyword(s):  
Coupling Reaction ◽  
Aryl Halides ◽  
Diazo Compounds ◽  
Reaction Pathways ◽  
Easy Access ◽  
Thiyl Radicals ◽  
Recent Advances ◽  
Sulfur Containing ◽  
Powerful Strategy ◽  
Sulfur Containing Compounds

The construction of a C-S bond is a powerful strategy for the synthesis of sulfur containing compounds including sulfides, sulfoxides, and sulfones. Recent methodological developments have revealed lots of novel protocols for C-S bond formation, providing easy access to sulfur containing compounds. Unlike traditional Ullmann typed C-S coupling reaction, the recently developed reactions frequently use non-halide compounds, such as diazo compounds and simple arenes/alkanes instead of aryl halides as substrates. On the other hand, novel C-S coupling reaction pathways involving thiyl radicals have emerged as an important strategy to construct C-S bonds. In this review, we focus on the recent advances on the synthesis of sulfides, sulfoxides, and sulfones from non-halide substrates involving C-S bond construction.

Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

2019 ◽  
Vol 16 (1) ◽  
pp. 173-180
Author(s):  
Mingwei Chen ◽  
Jinyu Hu ◽  
Xiaoli Tang ◽  
Qiming Zhu
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Metal Species ◽  
Good Substrate ◽  
Active Metal ◽  
Homocoupling Reaction ◽  
Catalytic Cycles ◽  
Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

Molecular Reconstruction of Hydrocarbons and Sulfur-Containing Compounds in Atmospheric and Vacuum Gas Oils

2021 ◽  
Author(s):  
Aleksandar Bojkovic ◽  
Thomas Dijkmans ◽  
Hang Dao Thi ◽  
Marko Djokic ◽  
Kevin M. Van Geem
Keyword(s):  
Sulfur Containing ◽  
Sulfur Containing Compounds

scholarly journals Effect of WC/Ni–Cr additive on changes in the composition of an atmospheric residue in the course of cracking

2019 ◽  
Vol 17 (2) ◽  
pp. 499-508 ◽  
Author(s):  
Galina S. Pevneva ◽  
Natalya G. Voronetskaya ◽  
Nikita N. Sviridenko ◽  
Anatoly K. Golovko
Keyword(s):  
Molecular Weight ◽  
Tungsten Carbide ◽  
Aromatic Hydrocarbons ◽  
Aromatic Compounds ◽  
Low Molecular Weight ◽  
Nickel Chromium ◽  
Atmospheric Residue ◽  
Sulfur Containing ◽  
Catalytic Additive ◽  
Sulfur Containing Compounds

AbstractThe paper presents the results of investigation of changes in the composition of hydrocarbons and sulfur-containing compounds of an atmospheric residue in the course of cracking in the presence of a tungsten carbide–nickel–chromium (WC/Ni–Cr) catalytic additive and without it. The cracking is carried out in an autoclave at 500 °C for 30 min. The addition of the WC/Ni–Cr additive promotes the deepening of reactions of destruction not only of resins and asphaltenes, but also high molecular weight naphthene-aromatic compounds of the atmospheric residue. It is shown that the content of low molecular weight C9–C17 n-alkanes and C9–C10 alkylbenzenes rose sharply in the products of cracking with addition of WC/Ni–Cr in comparison with those produced without the additive. Alkyl- and naphthene-substituted aromatic hydrocarbons of benzene, naphthalene, phenanthrene series, polyarenes, benzo- and dibenzothiophenes are identified.

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