scholarly journals Design and Synthesis of Aromatics through [2+2+2] Cyclotrimerization

Synlett ◽  
2018 ◽  
Vol 29 (18) ◽  
pp. 2342-2361 ◽  
Author(s):  
Sambasivarao Kotha ◽  
Kakali Lahiri ◽  
Gaddamedi Sreevani
Keyword(s):  
Amino Acids ◽  
Total Synthesis ◽  
Cycloaddition Reaction ◽  
Environmentally Friendly ◽  
Building Blocks ◽  
Cycloaddition Reactions ◽  
Chemical Transformations ◽  
Benzene Derivatives ◽  
Unusual Amino Acids ◽  
Design And Synthesis

The [2+2+2] cycloaddition reaction is a useful tool to realize unusual chemical transformations which are not achievable by traditional methods. Here, we report our work during the past two decades that involve utilization of transition-metal complexes in a [2+2+2] cyclotrimerization reaction. Several key “building blocks” were assembled by a [2+2+2] cycloaddition approach and they have been further expanded by other synthetic transformations to design unusual amino acids and peptides, diphenylalkanes, bis- and trisaryl benzene derivatives, annulated benzocycloalkanes, spirocycles, and spirooxindole derivatives. Furthermore, we have also discussed about alkyne surrogates, environmentally friendly, and stereoselective [2+2+2] cycloaddition reactions. Application of the [2+2+2] cycloaddition reaction in total synthesis is also covered. In this review we also included others work to give a balanced view of the recent developments in the area of [2+2+2] cycloaddition.1 Introduction2 Unusual Amino Acids and Peptides3 Heteroanalogues of Indane4 Diphenylalkane Derivatives5 Multi-Armed Aryl Benzene Derivatives6 Annulated Benzocycloalkanes7 Spirocycles8 Selectivity in [2+2+2] Cycloaddition of Alkynes9 [2+2+2] Cycloaddition Reactions under Environmentally Friendly Conditions10 Alkyne Surrogates11 Domino Reactions involving a [2+2+2] Cycloaddition12 Biologically Important Targets/Total Synthesis13 Conclusions

scholarly journals Syntheses of Cyclomarins – Interesting Marine Natural Products with Distinct Mode of Action towards Malaria and Tuberculosis

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 107-121 ◽  
Author(s):  
Alexander Kiefer ◽  
Uli Kazmaier
Keyword(s):  
Amino Acids ◽  
Plasmodium Falciparum ◽  
Natural Products ◽  
Total Synthesis ◽  
Building Blocks ◽  
Distinct Mode ◽  
Unusual Amino Acids ◽  
Caseinolytic Protease ◽  
A Subunit ◽  
Cyclomarin A

The cyclomarins are cyclic heptapeptides from marine streptomycetes containing four rather unusual amino acids. Interestingly, the cyclomarins address two completely different targets: ClpC1, a subunit of the caseinolytic protease of Mycobacterium tuberculosis (MTB), as well as PfAp3Aase of Plasmodium falciparum. Therefore, the cyclomarins are interesting lead structures for the development of drugs targeting tuberculosis and malaria. As a result, several synthetic protocols towards the synthesis of these unusual building blocks as well as the natural products themselves have been developed, which will be discussed in this review.1 Introduction2 Synthesis of the Building Blocks3 Total Synthesis of Cyclomarin C by Yao and Co-workers4 Total Synthesis of Cyclomarin A and C by Barbie and Kazmaier5 Conclusion

scholarly journals Huisgen [3 + 2] Dipolar Cycloadditions of Phthalazinium Ylides to Activated Symmetric and Non-Symmetric Alkynes

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4416
Author(s):  
Vasilichia Antoci ◽  
Costel Moldoveanu ◽  
Ramona Danac ◽  
Violeta Mangalagiu ◽  
Gheorghita Zbancioc
Keyword(s):  
Reaction Time ◽  
Comparative Study ◽  
Cycloaddition Reaction ◽  
Environmentally Friendly ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Dimethyl Acetylenedicarboxylate ◽  
Thermal Heating ◽  
Dipolar Cycloadditions ◽  
Methyl Propiolate

We present herein a straightforward and efficient pathway for the synthesis of pyrrolophthalazine cycloadducts via Huisgen [3 + 2] dipolar cycloaddition reactions of phthalazinium ylides to methyl propiolate or dimethyl acetylenedicarboxylate (DMAD). A thoroughly comparative study concerning the efficiency of synthesis, conventional thermal heating (TH) versus microwave (MW) and ultrasound (US) irradiation, has been performed. The cycloaddition reactions of phthalazinium ylides to methyl propiolate occur regiospecific, with a single regioisomer being obtained. Under conventional TH, the cycloaddition reaction of phthalazinium ylides with DMAD occurs to a mixture of inseparable partial and fully aromatized pyrrolophthalazine cycloadducts, while MW or US irradiation are leading only to fully aromatized compounds, with the reactions becoming selective. A feasible mechanism for formation of fully aromatized compounds is presented. Besides selectivity, it has to be noticed that the reaction setup under MW or US irradiation offer a number of other certain advantages: higher yields, decreasing of the amount of used solvent comparative with TH, decreasing of the reaction time from hours to minutes and decreasing of the consumed energy; consequently, these reactions could be considered environmentally friendly.

1,3-Dipolar Cycloadditions Involving Allenes: Synthesis of Five-Membered Rings

2020 ◽  
Vol 23 (27) ◽  
pp. 3064-3134 ◽  
Author(s):  
Ana L. Cardoso ◽  
Maria I.L. Soares
Keyword(s):  
Transition Metal ◽  
Cycloaddition Reaction ◽  
Building Blocks ◽  
Dipolar Cycloaddition ◽  
Cycloaddition Reactions ◽  
Relevant Research ◽  
Dipolar Cycloadditions ◽  
Recent Developments ◽  
Synthetic Equivalent ◽  
Metal Catalyzed

The 1,3-dipolar cycloaddition reaction is a powerful and versatile strategy for the synthesis of carbocyclic and heterocyclic five-membered rings. Herein, the most recent developments on the [3+2] cycloaddition reactions using allenes acting either as dipolarophiles or 1,3-dipole precursors, are highlighted. The recent contributions on the phosphine- and transition metal-catalyzed [3+2] annulations involving allenes as substrates are also covered, with the exception of those in which the formation of a 1,3-dipole (or synthetic equivalent) is not invoked. This review summarizes the most relevant research in which allenes are used as building blocks for the construction of structurally diverse five-membered rings via [3+2] annulation reactions.

scholarly journals The synthesis of a small library of prospective growth hormone secretagogues

1999 ◽  
Vol 64 (10) ◽  
pp. 571-576
Author(s):  
Vojislav Pejovic ◽  
Vukic Soskic ◽  
Jelena Joksimovic
Keyword(s):  
Amino Acids ◽  
Growth Hormone ◽  
Combinatorial Chemistry ◽  
Methodological Approach ◽  
Rabbit Antiserum ◽  
Building Blocks ◽  
Growth Hormone Secretagogues ◽  
Growth Hormone Secretagogue ◽  
Design And Synthesis ◽  
Polyclonal Rabbit Antiserum

Employing tools of combinatorial chemistry, an original methodological approach has been developed and applied for the design and synthesis of a small library of peptide-like compounds, prospective growth hormone (GH) secretagogues. For this purpose seven building blocks of tBoc- and Fmoc-protected amino acids was used. In this way, a small, tripeptoid library on polyethylene glycolmonomethyl ether 5000 (PEG 5000) as a soluble support was obtained. The library was screened by a new, simple system, based on polyclonal rabbit antiserum raised against "GH secretagogue pharmacophore" of a known growth hormone secretagogue GHRP-6 (Hexarelin?) and the most promising GH secretagogue candidate was selected.

Design and synthesis of protoporphyrin IX/vitamin B12 molecular hybrids viaCuAAC reaction

2013 ◽  
Vol 17 (01n02) ◽  
pp. 104-117 ◽  
Author(s):  
Rafał Loska ◽  
Anita Janiga ◽  
Dorota Gryko
Keyword(s):  
Vitamin B12 ◽  
Protoporphyrin Ix ◽  
Cycloaddition Reaction ◽  
Building Blocks ◽  
Water Soluble ◽  
Vitamin B ◽  
Design And Synthesis ◽  
Biological Studies ◽  
Molecular Hybrids ◽  
Vinyl Group

The design and synthesis of new molecular hybrids composed of protoporphyrin IX (PPIX) and vitamin B12 via copper catalyzed alkyne azide cycloaddition reaction is described. New, clickable aminoazide and aminoalkyne linkers were prepared and subsequently attached to PPIX (via vinyl group) and to vitamin B12 giving desired building blocks. Preliminary results showed that respective water soluble hybrids were formed under CuAAC reaction. Gratifyingly, Cu incorporation into the PPIX core was avoided, which was important for further biological studies.

A Short and Scalable Synthesis of Orthogonally Protected Bis(aminomethyl)malonic Acid: Access to Bioactive Macrocyclic Peptides

Synthesis ◽  
2017 ◽  
Vol 49 (22) ◽  
pp. 5039-5044
Author(s):  
Muthalagu Vetrichelvan ◽  
Vijayabhaskar Bokkala ◽  
Surendran Renganathan ◽  
Arvind Mathur ◽  
Richard Rampulla ◽  
...  
Keyword(s):  
Amino Acids ◽  
Natural Products ◽  
Total Synthesis ◽  
Malonic Acid ◽  
Good Yield ◽  
Building Blocks ◽  
Nucleophilic Attack ◽  
Macrocyclic Peptides ◽  
Scalable Synthesis ◽  
Key Steps

A short and scalable process for the preparation of multi-gram quantities of orthogonally protected bis(aminomethyl)malonic acid in good yield from readily available starting material is described. These orthogonally protected amino acids are important building blocks to make peptides based drugs, glycoconjugates, and in the total synthesis of peptide natural products. The newly developed route has only six steps with an overall yield of 27%, which involves nucleophilic attack of a malonate on an imide as one of the key steps.

scholarly journals Synthesis and Reactivity of Electron-Deficient 3-Vinylchromones

SynOpen ◽  
2021 ◽  
Vol 05 (03) ◽  
pp. 255-277
Author(s):  
Vyacheslav Y. Sosnovskikh
Keyword(s):  
Double Bond ◽  
Chemical Properties ◽  
Building Blocks ◽  
High Reactivity ◽  
Cycloaddition Reactions ◽  
Chemical Transformations ◽  
Pyrone Ring ◽  
The Past ◽  
Palladium Catalyzed ◽  
First Time

AbstractThe reported methods and data for the synthesis and reactivity of electron-deficient 3-vinylchromones containing electron-withdrawing­ groups at the exo-cyclic double bond are summarized and systematized for the first time. The main methods for obtaining these compounds are Knoevenagel condensation, Wittig reaction, and palladium-catalyzed cross-couplings. The most important chemical properties are transformations under the action of mono- and dinucleophiles, ambiphilic cyclizations, and cycloaddition reactions. The cross-conjugated and polyelectrophilic dienone system in 3-vinylchromones provides their high reactivity and makes these compounds valuable building blocks for the preparation of more complex heterocyclic systems. Chemical transformations of 3-vinylchromones usually begin with an attack of the C-2 atom and are accompanied by the opening of the pyrone ring followed by recyclization, in which the carbonyl group of chromone, an exo-double bond or a substituent on it can take part. The mechanisms of the reactions are discussed, the conditions for their implementation are described, and the yields of the resulting products are given. This review focuses on an analysis and generalization of the knowledge that has accumulated on the chemistry of electron-deficient 3-vinylchromones, mostly over the past 15 years.1 Introduction2 Synthesis of 3-Vinylchromones3 Reactions with Mononucleophiles4 Reactions with Dinucleophiles5 Ambiphilic Cyclization6 Cycloaddition Reactions7 Other Reactions8 Conclusion

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