scholarly journals Synthesis of 3,4-Bis(Butylselanyl)Selenophenes and 4-Alkoxyselenophenes Promoted by Oxone®

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2378
Author(s):  
Paola S. Hellwig ◽  
Jonatan S. Guedes ◽  
Angelita M. Barcellos ◽  
Gelson Perin ◽  
Eder J. Lenardão
Keyword(s):  
Transition Metal ◽  
Oxidative Cleavage ◽  
Aliphatic Alcohols ◽  
Electrophilic Cyclization ◽  
Metal Free ◽  
Selective Formation

We describe herein an alternative transition-metal-free procedure to access 3,4-bis(butylselanyl)selenophenes and the so far unprecedented 3-(butylselanyl)-4-alkoxyselenophenes. The protocol involves the 5-endo-dig electrophilic cyclization of 1,3-diynes promoted by electrophilic organoselenium species, generated in situ through the oxidative cleavage of the Se-Se bond of dibutyl diselenide using Oxone® as a green oxidant. The selective formation of the title products was achieved by controlling the solvent identity and the amount of dibutyl diselenide. By using 4.0 equiv of dibutyl diselenide and acetonitrile as solvent at 80 °C, four examples of 3,4-bis(butylselanyl)selenophenes were obtained in moderate to good yields (40–78%). When 3.0 equiv of dibutyl diselenide were used, in the presence of aliphatic alcohols as solvent/nucleophiles under reflux, 10 3-(butylselanyl)-4-alkoxyselenophenes were selectively obtained in low to good yields (15–80%).

Insertion Reaction of 2-Halo-N-allylanilines with K2S Involving Trisulfur Radical Anion: Synthesis of Benzothiazole Derivatives under Transition-Metal-Free Conditions

Synthesis ◽  
2020 ◽  
Author(s):  
Yan-Wei Zhao ◽  
Shun-Yi Wang ◽  
Xin-Yu Liu ◽  
Tian Jiang ◽  
Weidong Rao
Keyword(s):  
Transition Metal ◽  
Radical Anion ◽  
Radical Cyclization ◽  
Transition Metal Catalysis ◽  
Insertion Reaction ◽  
Metal Catalysis ◽  
Metal Free ◽  
Benzothiazole Derivatives

AbstractA synthesis of benzothiazole derivatives through the reaction of 2-halo-N-allylanilines with K2S in DMF is developed. The trisulfur radical anion S3·–, which is generated in situ from K2S in DMF, initiates the reaction without transition-metal catalysis or other additives. In addition, two C–S bonds are formed and heteroaromatization of benzothiazole is triggered by radical cyclization and H-shift.

Recent Developments in Transition-Metal-Free Functionalization and Derivatization Reactions of Pyridines

Synlett ◽  
2020 ◽  
Author(s):  
Lei Jiao ◽  
Fei-Yu Zhou
Keyword(s):  
Transition Metal ◽  
Structural Motif ◽  
Metal Exchange ◽  
Coupling Reactions ◽  
Phosphonium Salts ◽  
Metal Free ◽  
Radical Coupling ◽  
In Situ Activation ◽  
Recent Developments

AbstractPyridine is an important structural motif that is prevalent in natural products, drugs, and materials. Methods that functionalize and derivatize pyridines have gained significant attention. Recently, a large number of transition-metal-free reactions have been developed. In this review, we provide a brief summary of recent advances in transition-metal-free functionalization and derivatization reactions of pyridines, categorized according to their reaction modes.1 Introduction2 Metalated Pyridines as Nucleophiles2.1 Deprotonation2.2 Halogen–Metal exchange3 Activated Pyridines as Electrophiles3.1 Asymmetric 2-Allylation by Chiral Phosphite Catalysis3.2 Activation of Pyridines by a Bifunctional Activating Group3.3 Alkylation of Pyridines by 1,2-Migration3.4 Alkylation of Pyridines by [3+2] Addition3.5 Pyridine Derivatization by Catalytic In Situ Activation Strategies3.6 Reactions via Heterocyclic Phosphonium Salts4 Radical Reactions for Pyridine Functionalization4.1 Pyridine Functionalization through Radical Addition Reactions4.2 Pyridine Functionalization through Radical–Radical Coupling Reactions5 Derivatization of Pyridines through the Formation of Meisenheimer-Type Pyridyl Anions6 Conclusion

ChemInform Abstract: In situ Generation of PhI+CF3and Transition-Metal-Free Oxidative sp2C-H Trifluoromethylation.

ChemInform ◽  
2013 ◽  
Vol 44 (48) ◽  
pp. no-no
Author(s):  
Cong Xu ◽  
Jingxin Liu ◽  
Wenbo Ming ◽  
Yingjie Liu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Free ◽  
In Situ Generation

nBu4NOTf-promoted radical self-hydrogen transferring isomerization under transition metal-free conditions

2018 ◽  
Vol 5 (7) ◽  
pp. 1213-1216 ◽  
Author(s):  
Hong-Xing Zheng ◽  
Chuan-Zhi Yao ◽  
Jian-Ping Qu ◽  
Yan-Biao Kang
Keyword(s):  
Transition Metal ◽  
Metal Free

We report the first allylic isomerization of alcohols catalyzed by nBu4NOTf generated in situ from tetrabutylammonium triflate and potassium tert-butoxide.

Diastereoselective synthesis of spiro[cyclopropane-1,3′-indolin]-2′-ones through metal-free cyclopropanation using tosylhydrazone salts

RSC Advances ◽  
2014 ◽  
Vol 4 (72) ◽  
pp. 38425-38432 ◽  
Author(s):  
Jeevak Sopanrao Kapure ◽  
Chada Narsimha Reddy ◽  
Praveen Reddy Adiyala ◽  
Ranjita Nayak ◽  
V. Lakshma Nayak ◽  
...  
Keyword(s):  
Transition Metal ◽  
Diazo Compounds ◽  
Diastereoselective Synthesis ◽  
Metal Free

Anticancer spiro[cyclopropane-1,3′-indolin]-2′-ones are accessible through a transition metal-free diastereoselective cyclopropanation using in situ generated diazo-compounds.

In Situ Generation of PhI+ CF3 and Transition-Metal-Free Oxidative sp2 CH Trifluoromethylation

2013 ◽  
Vol 19 (28) ◽  
pp. 9104-9109 ◽  
Author(s):  
Cong Xu ◽  
Jingxin Liu ◽  
Wenbo Ming ◽  
Yingjie Liu ◽  
Jun Liu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Free ◽  
In Situ Generation
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