A practical metal-free homolytic aromatic alkylation protocol for the synthesis of 3-(pyrazin-2-yl)bicyclo[1.1.1]pentane-1-carboxylic acid

2016 ◽  
Vol 14 (40) ◽  
pp. 9485-9489 ◽  
Author(s):  
Navanita T. Thirumoorthi ◽  
Vikrant A. Adsool
Keyword(s):  
Carboxylic Acid ◽  
Building Block ◽  
Medicinal Chemistry ◽  
Biological Study ◽  
Metal Free

As a part of our ongoing synthetic quest to expand the frontiers of contemporary medicinal chemistry, we now report an expedient synthesis of a potentially useful bicyclo[1.1.1]pentane building block, 3-(pyrazin-2-yl)bicyclo[1.1.1]pentane-1-carboxylic acid. This report also showcases the application of this motif as a “spacer” probe in a biological study.

Direct Access to Highly Functionalised Benzimidazoles and Benzoxazoles from a Common Precursor

Synthesis ◽  
2019 ◽  
Vol 51 (21) ◽  
pp. 4006-4013 ◽  
Author(s):  
Amanda Garrido ◽  
Pierre-Olivier Delaye ◽  
François Quintin ◽  
Mohamed Abarbri ◽  
Pedro Lameiras ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Building Block ◽  
Medicinal Chemistry ◽  
Direct Access ◽  
One Pot ◽  
Metal Free ◽  
Mild Conditions ◽  
Common Precursor ◽  
Biological Interest ◽  
Wide Range

Benzoxazole and benzimidazole are commonly encountered heterocycles in medicinal chemistry and their functionalisation around 1-, 2-, 5-, and/or 6-positions provides a wide range of molecules of biological interest. In this manuscript, a straightforward preparation of diversely and highly substituted benzimidazoles and benzoxazoles on these positions, from a common starting material, a 3,3-dibromoacrolein, is described. Such acrolein derivatives are almost never described in the literature or used as ‘building-block’ for organic synthesis. The double electrophilicity of this substrate was found to be advantageous for condensation with two equivalents of various 1,2-diaminobenzene or 2-aminophenol derivatives. This one-pot reaction performed under metal-free and mild conditions allows the creation of three new carbon–heteroatom bonds and affords the desired heterocycles.

β-Diketone boron difluoride dye-functionalized conjugated microporous polymers for efficient aerobic oxidative photocatalysis

2021 ◽  
Author(s):  
Weitao Gong ◽  
Kaixun Dong ◽  
Lu Liu ◽  
Mehdi Hassan ◽  
Guiling Ning
Keyword(s):  
Building Block ◽  
Metal Free ◽  
Microporous Polymers ◽  
Boron Difluoride ◽  
Conjugated Microporous Polymers

Two new conjugated microporous polymers, TPB-B-CMP and TPA-B-CMP, with β-diketone-boron difluoride dye as the key building block were designed and successfully prepared. They were further employed as efficient metal-free heterogeneous photocatalysts.

Room-temperature Barbier single-atom polymerization induced emission as a versatile approach for the utilization of monofunctional carboxylic acid resources

2021 ◽  
Author(s):  
Quan-Xi Shi ◽  
Qian Li ◽  
Hang Xiao ◽  
Xiaoli Sun ◽  
Hongli Bao ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Building Block ◽  
Room Temperature ◽  
Single Atom ◽  
The Earth

Carboxylic acids are widely available from both biomass and fossil sources on the earth. In comparison with multifunctional carboxylic acid containing chemicals those have been comprehensively used as building block...

Five-Membered Hetarene N-Oxides: Recent Advances in Synthesis and Reactivity

Synthesis ◽  
2021 ◽  
Author(s):  
Leonid Fershtat ◽  
Fedor Teslenko
Keyword(s):  
Transition Metal ◽  
Medicinal Chemistry ◽  
Materials Science ◽  
State Of The Art ◽  
Short Review ◽  
Advanced Materials ◽  
Metal Free ◽  
Recent Advances ◽  
Application Potential ◽  
Metal Catalyzed

Five-membered heterocyclic N-oxides attracted special attention due to their strong application potential in medicinal chemistry and advanced materials science. In this regard, novel methods for their synthesis and functionalization are constantly required. In this short review, recent state-of-the-art achievements in the chemistry of isoxazoline N-oxides, 1,2,3-triazole 1-oxides and 1,2,5-oxadiazole 2-oxides are briefly summarized. Main routes to transition-metal-catalyzed and metal-free functionalization protocols along with mechanistic considerations are outlined. Transformation patterns of the hetarene N-oxide rings as precursors to other nitrogen heterocyclic systems are also presented.

Effect of Building Block Transformation in Covalent Triazine‐Based Frameworks for Enhanced CO 2 Uptake and Metal‐Free Heterogeneous Catalysis

2019 ◽  
Vol 26 (7) ◽  
pp. 1441-1441
Author(s):  
Himanshu Sekhar Jena ◽  
Chidharth Krishnaraj ◽  
Johannes Schmidt ◽  
Karen Leus ◽  
Kristof Van Hecke ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Building Block ◽  
Metal Free

Fluorescein Analogue Xanthene-9-Carboxylic Acid: A Transition-Metal-Free CO Releasing Molecule Activated by Green Light

2013 ◽  
Vol 15 (17) ◽  
pp. 4552-4555 ◽  
Author(s):  
Lovely Angel Panamparambil Antony ◽  
Tomáš Slanina ◽  
Peter Šebej ◽  
Tomáš Šolomek ◽  
Petr Klán
Keyword(s):  
Carboxylic Acid ◽  
Transition Metal ◽  
Green Light ◽  
Metal Free

Synthesis and singlet oxygen production of azaphthalocyanines bearing functional derivatives of carboxylic acid

2006 ◽  
Vol 10 (02) ◽  
pp. 122-131 ◽  
Author(s):  
Zbynek Musil ◽  
Petr Zimcik ◽  
Miroslav Miletin ◽  
Kamil Kopecky ◽  
Marek Link ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Singlet Oxygen ◽  
Hexanoic Acid ◽  
Oxygen Production ◽  
Metal Free ◽  
Dye Sensitized ◽  
Structure Activity ◽  
Functional Derivatives ◽  
Derivatives Of ◽  
Free Magnesium

New metal-free, magnesium and zinc azaphthalocyanines ( AzaPc ) were prepared from 6-(3-tert-butylsulfany1-5,6-dicyanopyrazine-2-ylamino)hexanoic acid and its butylester and N,N-diethylamide. Their singlet oxygen production was measured by a dye-sensitized photooxidation of 1,3-diphenylisobenzofuran ( DPBF ) and ΦΔ values were calculated. It was found that the presence of carboxylic acid in the structure of AzaPc decreases their singlet oxygen production. Singlet oxygen activity of the newly prepared compounds (containing mixed alkylamino and alkylsulfanyl peripheral substituents) lies between purely alkylsulfanyl and alkylamino derivatives of AzaPc . This fact further supports previously proposed structure-activity relationships, where alkylsulfanyl derivatives belong to the best singlet oxygen producers while the presence of alkylamino substituents in the structure rapidly decreases their photodynamic properties.

Synthesis of an Oxaspirolactone Intermediate for the Synthesis of Spirolides

2000 ◽  
Vol 53 (10) ◽  
pp. 845 ◽  
Author(s):  
Margaret A. Brimble ◽  
Fares A. Fares ◽  
Peter Turner
Keyword(s):  
Carboxylic Acid ◽  
Single Crystal ◽  
Building Block ◽  
New Method ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

A new method has been established for the preparation of C 2-oxidized 5,5-spiroacetals, which are key intermediates for the synthesis of the bis-spiroacetal moiety of the spirolides. A bridged orthoester was used as a masked carboxylic acid in the preparation of these bicyclic oxaspirolactones. The synthesis of chiral lactone (12), a building block for the synthesis of the spirolides, is also reported. The two chiral centres in lactone (12) were assembled by addition of a chiral crotyl borane to an aldehyde. The structure of lactone (12) was determined by single-crystal X-ray diffraction; orthorhombic space group P212121 (No. 19), a 12.437(2), b 23.881(4), c 7.545(1) Å, V 2240.9(5) Å3, R(F) 0.0460, and Rw(F) 0.0458.

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