scholarly journals Total synthesis of TMG-chitotriomycin based on an automated electrochemical assembly of a disaccharide building block

2017 ◽  
Vol 13 ◽  
pp. 919-924 ◽  
Author(s):  
Yuta Isoda ◽  
Norihiko Sasaki ◽  
Kei Kitamura ◽  
Shuji Takahashi ◽  
Sujit Manmode ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Solution Phase ◽  
Protecting Groups ◽  
Phase Synthesis ◽  
Solution Phase Synthesis

The total synthesis of TMG-chitotriomycin using an automated electrochemical synthesizer for the assembly of carbohydrate building blocks is demonstrated. We have successfully prepared a precursor of TMG-chitotriomycin, which is a structurally-pure tetrasaccharide with typical protecting groups, through the methodology of automated electrochemical solution-phase synthesis developed by us. The synthesis of structurally well-defined TMG-chitotriomycin has been accomplished in 10-steps from a disaccharide building block.

scholarly journals Solution phase synthesis of short oligoribonucleotides on a precipitative tetrapodal support

2014 ◽  
Vol 10 ◽  
pp. 2279-2285 ◽  
Author(s):  
Alejandro Gimenez Molina ◽  
Amit M Jabgunde ◽  
Pasi Virta ◽  
Harri Lönnberg
Keyword(s):  
Building Block ◽  
Rna Synthesis ◽  
Building Blocks ◽  
Solution Phase ◽  
Dipolar Cycloaddition ◽  
Proof Of Concept ◽  
Phase Synthesis ◽  
Solution Phase Synthesis ◽  
High Yields

An effective method for the synthesis of short oligoribonucleotides in solution has been elaborated. Novel 2'-O-(2-cyanoethyl)-5'-O-(1-methoxy-1-methylethyl) protected ribonucleoside 3'-phosphoramidites have been prepared and their usefulness as building blocks in RNA synthesis on a soluble support has been demonstrated. As a proof of concept, a pentameric oligoribonucleotide, 3'-UUGCA-5', has been prepared on a precipitative tetrapodal tetrakis(4-azidomethylphenyl)pentaerythritol support. The 3'-terminal nucleoside was coupled to the support as a 3'-O-(4-pentynoyl) derivative by Cu(I) promoted 1,3-dipolar cycloaddition. Couplings were carried out with 1.5 equiv of the building block. In each coupling cycle, the small molecular reagents and byproducts were removed by two quantitative precipitations from MeOH, one after oxidation and the second after the 5'-deprotection. After completion of the chain assembly, treatment with triethylamine, ammonia and TBAF released the pentamer in high yields.

Synthesis of Optically Active 15-epi-9,14-Methylene Lipoxin A4

Synthesis ◽  
2018 ◽  
Vol 50 (06) ◽  
pp. 1246-1258
Author(s):  
Udo Nubbemeyer ◽  
Adile Duymaz ◽  
Jochen Körber ◽  
Carolin Hofmann ◽  
Dorothea Gerlach
Keyword(s):  
Total Synthesis ◽  
Building Block ◽  
Building Blocks ◽  
Optically Active ◽  
Protecting Groups ◽  
Lipoxin A4 ◽  
Methylene Bridge ◽  
Type Coupling ◽  
Important Field ◽  
Gain Access

The synthesis of lipoxin A4 and B4 analogues (LXA4, LXB4) to gain access to stabilized inflammation resolving compounds is an important field of research. Starting from known structural requirements of the natural compounds displaying biological activity and a broad investigation of their rapid metabolism, various LXA4 derivatives have been developed and tested. Focusing on variation and stabilization of the conjugated E,E,Z,E C7–C14 tetraene moiety of natural LXA4, a methylene bridge introduced between C9 and C14 might suppress any Z/E isomerization of the C11–C12 olefin. Intending to enable at least known structure variations in connection with the C1–C7 and the C15–C20 fragments, a convergent total synthesis starting from a known cycloheptatriene is developed. The C1–C8 building blocks are generated via six-step ex-chiral pool sequences starting from 2-deoxy-d-ribose delivering two 5,6-dihydroxy carboxylic acid derivatives with C7 aldehyde functions. The synthesis of the C8–C21 building block starts from a known cycloheptatriene 1-carbonester (C8–C14, C21) and hexanoyl chloride (C15–C20). After Friedel–Crafts-type coupling, the defined configuration of the C15 OH group is introduced via enantioselective reduction of the ketone precursor. Following an additional four steps, an aryl sulfone C9–C21 building block is completed ready for a key Julia–Kocienski olefination with the C1–C7 compounds. Finally, removal of the protecting groups completes the synthesis of the target optically active 9,14-methylene LXA4 methyl ester.

scholarly journals Preparation of a disulfide-linked precipitative soluble support for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks

2015 ◽  
Vol 11 ◽  
pp. 1553-1560 ◽  
Author(s):  
Amit M Jabgunde ◽  
Alejandro Gimenez Molina ◽  
Pasi Virta ◽  
Harri Lönnberg
Keyword(s):  
Disulfide Bond ◽  
Building Blocks ◽  
Reductive Cleavage ◽  
Solution Phase ◽  
Phase Synthesis ◽  
Solution Phase Synthesis

The preparation of a disulfide-tethered precipitative soluble support and its use for solution-phase synthesis of trimeric oligodeoxyribonucleotide 3´-(2-chlorophenylphosphate) building blocks is described. To obtain the building blocks, N-acyl protected 2´-deoxy-5´-O-(4,4´-dimethoxytrityl)ribonucleosides were phosphorylated with bis(benzotriazol-1-yl) 2-chlorophenyl phosphate. The “outdated” phosphotriester strategy, based on coupling of PV building blocks in conjunction with quantitative precipitation of the oligodeoxyribonucleotide with MeOH is applied. Subsequent release of the resulting phosphate and base-protected oligodeoxyribonucleotide trimer 3’-pTpdCBzpdGibu-5’ as its 3’-(2-chlorophenyl phosphate) was achieved by reductive cleavage of the disulfide bond.

scholarly journals Solution Phase Synthesis and Workup Using an Integrated Approach

2003 ◽  
Vol 8 (2) ◽  
pp. 41-43
Author(s):  
Lewin T. Wint ◽  
Marija Kovacevic ◽  
Matt Waters ◽  
Mettler-Toledo AutoChem
Keyword(s):  
Organic Synthesis ◽  
Integrated Approach ◽  
Building Blocks ◽  
Solution Phase ◽  
Automated System ◽  
Automated Systems ◽  
Time Saving ◽  
Phase Synthesis ◽  
Drug Candidates ◽  
Solution Phase Synthesis

Traditional organic synthesis is often cumbersome and time consuming. Significant effort by manufacturers of automated systems has been directed at increasing the speed, efficiency, and consistency of performing chemical reactions. To date, the numbers of integrated systems that combine all the relevant steps of compound preparation are few. Using the five automated systems in tandem can successfully streamline research and development of potential drug candidates. The features of these workstations offer a unique approach for supporting the convenient synthesis and workup of diverse compounds without compromising reagent types or conditions used for synthesis. This poster details an example of the automated drug discovery approach to high throughput organic synthesis using the solution phase synthesis of a series of 1-indanones as building blocks and subsequent reductive amination reactions to generate a diverse group of amines. The purpose of each automated system is outlined along with its role in generating the small library as an illustration of the importance of time saving devices in laboratories.

Synthesis of Yolk-Shell Co3O4/Co1-xRuxO2 Microspheres Featuring an Enhanced Electrocatalytic Oxygen Evolution in Acidic Medium

2021 ◽  
Author(s):  
Abinaya Annamalai ◽  
Dipak Vijaykumar Shinde ◽  
Joka Buha ◽  
Sergio Marras ◽  
Mirko Prato ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Acidic Medium ◽  
Building Blocks ◽  
Solution Phase ◽  
Phase Synthesis ◽  
Hollow Structures ◽  
Solution Phase Synthesis ◽  
Electrochemical Water Splitting

Hollow structures made of nanoscale building blocks are of great interest as catalysts for electrochemical water splitting. Here we report a solution-phase synthesis of yolk-shell Co3O4/Co1-xRuxO2 microspheres (MSs) having a...

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