Metal-Free Blue-Light-Mediated Cyclopropanation of Indoles by Aryl(diazo)acetates

Synthesis ◽  
2018 ◽  
Vol 51 (04) ◽  
pp. 889-898 ◽  
Author(s):  
Jun-Long Niu ◽  
Mao-Ping Song ◽  
Xing Zhang ◽  
Cong Du ◽  
He Zhang ◽  
...  
Keyword(s):  
Energy Source ◽  
Blue Light ◽  
Environmentally Friendly ◽  
Metal Free ◽  
Mild Conditions ◽  
Salient Features ◽  
Sole Energy

Blue-light-mediated cyclopropanation of indoles with aryl(diazo)acetates has been developed. The salient features of this strategy are that it is metal-free, operationally simple and atom-efficient, and that it uses an environmentally friendly energy source. In this protocol, blue light was employed as the sole energy source for the transformation. A variety of cyclopropane-fused indoline compounds was obtained in moderate to excellent yields and high diastereoselectivities under mild conditions.

scholarly journals Transition metal-free photodecarboxylative amination of redox-active esters with diazirines

2021 ◽  
Author(s):  
Vishala Maharaj ◽  
Preeti Chandrachud ◽  
Wen Che ◽  
Lukasz Wojtas ◽  
Justin Lopchuk
Keyword(s):  
Transition Metal ◽  
Blue Light ◽  
Electrophilic Amination ◽  
Metal Free ◽  
Active Esters ◽  
Mild Conditions ◽  
Redox Active ◽  
The Stability ◽  
Nitrogen Containing Compounds ◽  
Intense Research

Due to the prevalence of nitrogen-containing compounds in medicine, materials, and related fields, the search for general, mild methods for electrophilic amination remains an area of intense research. Diazirines have been recently demonstrated to serve as electrophilic amination reagents that afford diaziridines, versatile heterocycles that are readily transformed into amines, hydrazines, and a variety of nitrogen-containing heterocycles. Here we report the phosphine-mediated, photodecarboxylative amination of redox-active esters with diazirines. This method is transition metal-free, uses inexpensive photoactivators under mild conditions, and offers a significantly enhanced scope and yields for primary redox-active esters. Furthermore, the stability of diazirines to blue light (456 nm) is demonstrated, paving the way for further research into other photochemical amination methods with these unique heterocycles.

Metal-free n-Et4NBr-catalyzed radical cyclization of disulfides and alkynes leading to benzothiophenes under mild conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (89) ◽  
pp. 48547-48553 ◽  
Author(s):  
Daoshan Yang ◽  
Kelu Yan ◽  
Wei Wei ◽  
Laijin Tian ◽  
Qinghe Li ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Bond Formation ◽  
Environmentally Friendly ◽  
Radical Cyclization ◽  
Title Reaction ◽  
Metal Free ◽  
Mild Conditions

The title reaction involves metal free TEAB-catalyzed S–S bond cleavage, C–S bond formation and C–C bond formation; it uses readily available disulfides and alkynes as substrates, and environmentally friendly TEAB as catalyst to synthesize useful benzothiophene derivatives.

A Sequential Ugi-Smiles / Transition-Metal-Free Endo-Dig Conia-ene Cyclization: The Selective Synthesis of Saccharin Substituted 2,5-dihydropyrroles

2021 ◽  
Author(s):  
Hassan Seyrani ◽  
Sorour Ramezanpour ◽  
Aref Vaezghaemi ◽  
Farzad Kobarfard
Keyword(s):  
Transition Metal ◽  
Free Access ◽  
Selective Synthesis ◽  
Metal Free ◽  
Mild Conditions

A convenient, transition-metal-free access to a series of unprecedented saccharin substituted 2,5-dihydropyrroles is reported. This approach employs a post-Ugi-Smiles 5-endo-dig Conia-ene cyclization sequence in mild conditions while incorporating a series...

Metal‐free direct oxidative C–N bond coupling of quinoxalin‐2(1H)‐ones with azoles under mild conditions

2021 ◽  
Author(s):  
Jingwen Guo ◽  
Lina Zhang ◽  
Xinyue Du ◽  
Liting Zhang ◽  
Yuepiao Cai ◽  
...  
Keyword(s):  
Metal Free ◽  
Mild Conditions

A metal-free radical cascade reaction of phosphine oxides with 2-aryloxy phenylacetylenes to assemble diphosphonyl xanthene derivatives

2021 ◽  
Author(s):  
Tao Fan ◽  
Yan Liu ◽  
Caina Jiang ◽  
Yanli Xu ◽  
Yan-Yan Chen
Keyword(s):  
Free Radical ◽  
Transition Metal ◽  
Cascade Reaction ◽  
Phosphine Oxides ◽  
Metal Free ◽  
Mild Conditions ◽  
Xanthene Derivatives ◽  
Reaction Proceeds ◽  
Radical Cascade

A radical cascade reaction of 2-aryloxy phenylacetylene with phosphine oxides promoted by K2S2O8 was developed, provided diphosphonyl xanthenes as products. This reaction proceeds under transition metal-free and mild conditions with...

scholarly journals An entry to 2-(cyclobut-1-en-1-yl)-1H-indoles through a cyclobutenylation/deprotection cascade

2021 ◽  
Author(s):  
Philipp Natho ◽  
Zeyu Yang ◽  
Lewis Allen ◽  
Juliette Rey ◽  
Andrew J P White ◽  
...  
Keyword(s):  
Transition Metal ◽  
One Pot ◽  
Metal Free ◽  
Mild Conditions

A transition-metal-free strategy for the synthesis of 2-(cyclobut-1-en-1-yl)-1H-indoles under mild conditions is described herein. A series of substituted 2-(cyclobut-1-en-1-yl)-1H-indoles are accessed by a one-pot cyclobutenylation/deprotection cascade from N-Boc protected indoles....

scholarly journals Homocoupling of terminal alkynes catalyzed by CuCl under solvent-free conditions

2021 ◽  
pp. 174751982110325
Author(s):  
Yan Xiao ◽  
Jiyu Gao ◽  
Peng Chen ◽  
Guangliang Chen ◽  
Zicheng Li ◽  
...  
Keyword(s):  
Functional Group ◽  
Reaction Times ◽  
Environmentally Friendly ◽  
Solvent Free ◽  
Copper Salt ◽  
Terminal Alkynes ◽  
Mild Conditions ◽  
Solvent Free Conditions ◽  
Environmentally Friendly Process

A series of symmetrical 1,4-disubstituted buta-1,3-diynes is prepared with excellent yields (up to 95%) through homocoupling of terminal alkynes catalyzed by a copper salt under solvent-free conditions. This method provides an environmentally friendly process to prepare 1,3-diynes in short reaction times under mild conditions. Furthermore, the method is suitable for a wide substrate scope and has excellent functional group compatibility. The reaction can also be scaled up to gram level.

scholarly journals Recent Advances in Rapid Synthesis of Non-proteinogenic Amino Acids from Proteinogenic Amino Acids Derivatives via Direct Photo-Mediated C–H Functionalization

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5270
Author(s):  
Zhenbo Yuan ◽  
Xuanzhong Liu ◽  
Changmei Liu ◽  
Yan Zhang ◽  
Yijian Rao
Keyword(s):  
Amino Acids ◽  
Direct Synthesis ◽  
Environmentally Friendly ◽  
Powerful Method ◽  
Rapid Synthesis ◽  
Conservation Of Energy ◽  
Mild Conditions ◽  
Recent Advances ◽  
Recent Developments

Non-proteinogenic amino acids have attracted tremendous interest for their essential applications in the realm of biology and chemistry. Recently, rising C–H functionalization has been considered an alternative powerful method for the direct synthesis of non-proteinogenic amino acids. Meanwhile, photochemistry has become popular for its predominant advantages of mild conditions and conservation of energy. Therefore, C–H functionalization and photochemistry have been merged to synthesize diverse non-proteinogenic amino acids in a mild and environmentally friendly way. In this review, the recent developments in the photo-mediated C–H functionalization of proteinogenic amino acids derivatives for the rapid synthesis of versatile non-proteinogenic amino acids are presented. Moreover, postulated mechanisms are also described wherever needed.

Metal-Free Synthesis of Highly Substituted Pyridines by Formal [2+2+2] Cycloaddition under Mild Conditions

2016 ◽  
Vol 128 (41) ◽  
pp. 13056-13059 ◽  
Author(s):  
Lan-Gui Xie ◽  
Saad Shaaban ◽  
Xiangyu Chen ◽  
Nuno Maulide
Keyword(s):  
Metal Free ◽  
Mild Conditions ◽  
Substituted Pyridines
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