Base mediated 7-exo-dig intramolecular cyclization of Ugi–propargyl precursors: a highly efficient and regioselective synthetic approach toward diverse 1,4-benzoxazepine-5(2H)-ones

2014 ◽  
Vol 12 (29) ◽  
pp. 5346-5350 ◽  
Author(s):  
Shashi Pandey ◽  
S. Vinod Kumar ◽  
Ruchir Kant ◽  
Prem M. S. Chauhan
Keyword(s):  
Intramolecular Cyclization ◽  
Synthetic Approach ◽  
Metal Free ◽  
Highly Efficient

A metal-free facile and efficient two-step synthetic protocol for the preparation of 1,4-benzoxazepine-5(2H)-one derivatives has been developed.

Metal free decarboxylative aminoxylation of carboxylic acids using a biphasic solvent system

2021 ◽  
Vol 19 (1) ◽  
pp. 273-278
Author(s):  
Göran Schulz ◽  
Andreas Kirschning
Keyword(s):  
Carboxylic Acids ◽  
Solvent System ◽  
Radical Scavenger ◽  
Synthetic Approach ◽  
Metal Free ◽  
System P

The oxidative radical decarboxylation of carboxylic acids with TEMPO as radical scavenger in a biphasic solvent system is reported which is successfully used in a new synthetic approach for the antidepressants indatraline.

Highly efficient metal-free electro-Fenton degradation of organic contaminants on a bifunctional catalyst

2021 ◽  
Vol 416 ◽  
pp. 125859
Author(s):  
Xin Qin ◽  
Kun Zhao ◽  
Xie Quan ◽  
Peike Cao ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Bifunctional Catalyst ◽  
Metal Free ◽  
Highly Efficient

scholarly journals Author Correction: A metal-free photocatalyst for highly efficient hydrogen peroxide photoproduction in real seawater

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingyao Wu ◽  
Jingjing Cao ◽  
Xiao Wang ◽  
Yan Liu ◽  
Yajie Zhao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Metal Free ◽  
Highly Efficient

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-21490-z

Intramolecular Diels–Alder Reactions of Oxazoles, Imidazoles, and Thiazoles

Synthesis ◽  
2020 ◽  
Author(s):  
Peter Wipf ◽  
Thanh T. Nguyen
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Copper Catalysts ◽  
Diels Alder ◽  
Synthetic Approach ◽  
Highly Efficient ◽  
Intramolecular Cycloadditions ◽  
Western Segment ◽  
Target Molecules

AbstractThe development of the intramolecular Diels–Alder cycloaddition­ of azole heterocycles, i.e. oxazoles (IMDAO), imidazoles (IMDAI), and thiazoles (IMDAT), has had a significant impact on the efficient preparation of heterocyclic intermediates and natural products. In particular, highly efficient and versatile IMDAO reactions have been utilized as a key step in several synthetic schemes to provide alkaloids and terpenoid target molecules. More limited studies have been performed on IMDAI and IMDAT cycloadditions. Some drawbacks, such as the occasionally­ challenging preparation of IMDA precursors, are also highlighted in this review. Perspectives are provided on how IMDAI and IMDAT­ transformations can be further expanded for target-directed syntheses.1 Introduction2 Oxazoles2.1 IMDAO Approaches to Furanosesquiterpenes and Furanosteroids2.1.1 Syntheses of Highly Oxygenated Sesquiterpenes2.1.2 Syntheses of (±)-Gnididione and (±)-Isognididione2.1.3 Synthesis of (±)-Stemoamide2.1.4 Synthesis of (±)-Paniculide A2.1.5 Syntheses of (+)- and (–)-Norsecurinine2.1.6 Synthesis of Evodone2.1.7 Syntheses of (±)-Ligularone and (±)-Petasalbine2.1.8 Syntheses of Imerubrine, Isoimerubrine, and Grandirubrine2.1.9 Syntheses of Furanosteroids2.1.10 Syntheses of Substituted Indolines and Tetrahydroquinolines2.2 IMDAO Approaches to Pyridines: the Kondrat’eva Reaction2.2.1 Syntheses of Suaveoline and Norsuaveoline2.2.2 Synthesis of Eupolauramine2.2.3 Syntheses of (–)-Plectrodorine and (+)-Oxerine2.2.4 Synthesis of Amphimedine2.2.5 Synthetic Approach to the Western Segment of Haplophytine2.2.6 Synthesis of Marinoquinoline A2.2.6.1 IMDAO Approach to Marinoquinoline A2.2.6.2 Scope of Allenyl IMDAO Cycloaddition2.3 Lewis Acid Catalysis in IMDAO Reactions2.3.1 Effects of Europium Catalysts on IMDAO Reactions2.3.2 Effects of Copper Catalysts on IMDAO Reactions3 Imidazoles 4 Thiazoles4.1 Syntheses of Menthane and Eremophilane4.2 Further Comments on the Intramolecular Cycloadditions of Thiocarbonyl Ylides5 Conclusions and Outlook

Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one

2019 ◽  
Vol 17 (2) ◽  
pp. 380-387 ◽  
Author(s):  
Shuai Zou ◽  
Shu Geng ◽  
Lina Chen ◽  
Haitao Wang ◽  
Feng Huang
Keyword(s):  
Visible Light ◽  
Intramolecular Cyclization ◽  
Facile Synthesis ◽  
Metal Free ◽  
Visible Light Driven

Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one.

Boron nitride supported NiCoP nanoparticles as noble metal-free catalyst for highly efficient hydrogen generation from ammonia borane

2019 ◽  
Vol 44 (10) ◽  
pp. 4764-4770 ◽  
Author(s):  
Xin Zhou ◽  
Xu-Feng Meng ◽  
Jun-Min Wang ◽  
Ning-Zhao Shang ◽  
Tao Feng ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Noble Metal ◽  
Hydrogen Generation ◽  
Ammonia Borane ◽  
Metal Free ◽  
Highly Efficient

Microwave irradiated synthesis of 2-bromo(chloro)indoles via intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in the presence of TBAF under metal-free conditions

RSC Advances ◽  
2014 ◽  
Vol 4 (51) ◽  
pp. 26918-26923 ◽  
Author(s):  
Min Wang ◽  
Pinhua Li ◽  
Wei Chen ◽  
Lei Wang
Keyword(s):  
Microwave Irradiation ◽  
Intramolecular Cyclization ◽  
Metal Free

2-Bromo(chloro)indoles were readily prepared through TBAF-promoted intramolecular cyclization of 2-(gem-dibromo(chloro)vinyl)anilines in excellent yields under metal-free and microwave irradiation conditions.

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