scholarly journals Recent Progress in Transition Metal-Free C-Heteroatom Bond Formation by Functionalization of C-H Bond in Imidazole-Fused Heterocycles

2019 ◽  
Vol 39 (12) ◽  
pp. 3338 ◽  
Author(s):  
Xinming Xu ◽  
Demao Chen ◽  
Zuli Wang
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Bond Formation ◽  
Metal Free ◽  
Fused Heterocycles

Facile Access to Triazole-Fused 3,1-Benzoxazines Enabled by Metal-Free Base-Promoted Intramolecular C–O Coupling

Synthesis ◽  
2021 ◽  
Author(s):  
Yury N. Kotovshchikov ◽  
Stepan S. Tatevosyan ◽  
Gennadij V. Latyshev ◽  
Nikolay V. Lukashev ◽  
Irina P. Beletskaya
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Cost Effective ◽  
Reductive Cleavage ◽  
Effective Procedure ◽  
Free Base ◽  
Metal Free ◽  
Fused Heterocycles ◽  
Convenient Approach

AbstractA convenient approach to assemble 1,2,3-triazole-fused 4H-3,1-benzoxazines has been developed. Diverse alcohol-tethered 5-iodotriazoles, readily accessible by a modified protocol of Cu-catalyzed (3+2)-cycloaddition, were utilized as precursors of the target fused heterocycles. The intramolecular C–O coupling proceeded efficiently under base-mediated transition-metal-free conditions, furnishing cyclization products in yields up to 96%. Suppression of the competing reductive cleavage of the C–I bond was achieved by the use of Na2CO3 in acetonitrile at 100 °C. This practical and cost-effective procedure features a broad substrate scope and valuable functional group tolerance.

Transition-Metal-Free Catalysis for the Reductive ­Functionalization of CO2 with Amines

Synlett ◽  
2018 ◽  
Vol 29 (05) ◽  
pp. 548-555 ◽  
Author(s):  
Liang-Nian He ◽  
Xiao-Fang Liu ◽  
Xiao-Ya Li ◽  
Chang Qiao
Keyword(s):  
Transition Metal ◽  
Energy Content ◽  
Bond Formation ◽  
Energy Storage Materials ◽  
One Pot ◽  
Metal Free ◽  
Recent Developments ◽  
Electron Reduction ◽  
Reduction Of Co2 ◽  
Hierarchical Reduction

Reductive functionalization of CO2 with amines and a reductant, which combines both reduction of CO2 and C–N bond formation in one pot to produce versatile chemicals and energy-storage materials such as formamides, aminals, and methylamines that are usually derived from petroleum feedstock, would be appealing and promising. Herein, we give a brief review on recent developments in the titled CO2 chemistry by employing transition-metal-free catalysis, which can be catalogued as below according to the diversified energy content of the products, that is formamides, aminals, and methylamines being consistent with 2-, 4-, and 6-electron reduction of CO2, respectively. Notably, hierarchical reduction of CO2 with amines to afford at least two products, for example, formamides and methylamines, could be realized with the same catalyst through tuning the hydrosilane type, reaction temperature, or CO2 pressure. Finally, the opportunities and challenges of the reductive functionalization of CO2 with amines are also highlighted.1 Introduction2 2-Electron Reduction of CO2 to Formamide3 6-Electron Reduction of CO2 to Methylamine4 4-Electron Reduction of CO2 to Aminal5 Hierarchical Reduction of CO2 with Amines6 Conclusion

scholarly journals Synthesis of Polyhedral Borane Cluster Fused Heterocycles via Transition Metal Catalyzed B-H Activation

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 391 ◽  
Author(s):  
Ke Cao ◽  
Cai-Yan Zhang ◽  
Tao-Tao Xu ◽  
Ji Wu ◽  
Xin-Yu Wen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Building Blocks ◽  
Bioactive Natural Products ◽  
Fused Heterocycles ◽  
Selective Functionalization ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Photoluminescent Materials ◽  
Borane Cluster

Aromatic heterocycles are ubiquitous building blocks in bioactive natural products, pharmaceutical and agrochemical industries. Accordingly, the carborane-fused heterocycles would be potential candidates in drug discovery, nanomaterials, metallacarboranes, as well as photoluminescent materials. In recent years, the transition metal catalyzed B-H activation has been proved to be an effective protocol for selective functionalization of B-H bond of o-carboranes, which has been further extended for the synthesis of polyhedral borane cluster-fused heterocycles via cascade B-H functionalization/annulation process. This article summarizes the recent progress in construction of polyhedral borane cluster-fused heterocycles via B-H activation.

Metal-Free Catalytic Aromatic C–H Borylation

Synlett ◽  
2020 ◽  
Vol 31 (19) ◽  
pp. 1857-1861
Author(s):  
Hua Zhang ◽  
Li Wang
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Rapid Development ◽  
Transition Metal Catalysis ◽  
Mechanistic Studies ◽  
Metal Catalysis ◽  
Promising Alternative ◽  
Metal Free ◽  
History Of ◽  
Near Future

In recent decades, C–H borylation has undergone rapid development and has become one of the most important and efficient methods for the synthesis of organoboron compounds. Although transition-metal catalysis dominates C–H borylation, the metal-free approach has emerged as a promising alternative strategy. This article briefly summarizes the history of metal-free aromatic C–H borylation, including early reports on electrophilic C–H borylation and recent progress in metal-free catalytic intermolecular C–H borylation; it also highlights our recent work on BF3·Et2O-catalyzed C2–H borylation of hetarenes. Despite these recent advances, comprehensive mechanistic studies on various metal-free catalytic aromatic C–H borylations and novel processes with a wider substrate scope are eagerly expected in the near future.

Recent Advances in Radical Initiated C-N Bond Formation under Transition Metal-Free Conditions

2017 ◽  
Vol 37 (3) ◽  
pp. 566 ◽  
Author(s):  
Sitian Yuan ◽  
Yanhua Wang ◽  
Guanyinsheng Qiu ◽  
Jinbiao Liu
Keyword(s):  
Transition Metal ◽  
Bond Formation ◽  
Metal Free ◽  
Recent Advances
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