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Palladium Catalyzed Intramolecular Cyclization and C-H Activation Reaction Interesting Tool for the Synthesis of Some Exquisite Molecules

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Palladium Catalyzed Intramolecular Cyclization and C-H Activation Reaction Interesting Tool for the Synthesis of Some Exquisite Molecules
Jayanta Kumar Ray

Prayogic Rasayan 2021, 5, 1-6

DOI: https://www.doi.org/10.53023/p.rasayan-20210315


We have successfully investigated the palladium catalyzed cyclization in diene system to the formation of three unusual products. By varying the reaction conditions, we observed the formation of fused cyclopentane-cyclopropane rings, fused cyclopentane-cyclopentane rings or benzene ring formation from similar types of diene substrates. The most unexpected and unusual step, the formation of cyclopropane, was studied using density functional theory based calculations.

Lycopodium Alkaloids from Thai Club Mosses
Chuleeporn Ngernnak, Wachirasak Thaisaeng, Wanlaya Thamnarak, Somsak Ruchirawat, Nopporn Thasana

Prayogic Rasayan 2021, 5, 7-22

DOI: https://www.doi.org/10.53023/p.rasayan-20210526


This review focuses on the structural classification of t he Lycopodium alkaloids (LAs) isolated from seven species of Thai club mosses and their biological activities, especially acetylcholinesterase inhibitory activity.The structures of 38 LAs are presented and some isolated LAs were potent acetylcholinesterase (AChE) inhibitors. The content of huperzine A in the club moss species was evaluated for biological activities.

Green synthesis of zinc oxide nanoparticles, their characterization and utilization for photocatalytic removal of methylene blue
Rahul Patwa, Nabanita Saha, Petr Saha

Prayogic Rasayan 2021, 5, 23-26

DOI: https://www.doi.org/10.53023/p.rasayan-20210410


We report a facile synthesis of zinc oxide nanoparticles by green chemistry utilizing fresh lemon juice, zinc acetate and ethylene glycol. The prepared ZnO NPs were characterized using FTIR spectroscopy, X-ray diffraction analysis, DLS, FESEM and EDAX. The particles were found to be hexagonal wurtzite form having average particle size ~250 nm. The developed ZnO-NPs showed photocatalytic degradation of the artificial dye Methylene Blue under UV light irradiation at 365 nm.

Liquid Crystals: A Fascinating Fourth State of Matter
Sachin A. Bhat, Madhu Babu Kanakala, Channabasaveshwar V.Yelamaggad

Prayogic Rasayan 2021, 5, 27-36

DOI: https://www.doi.org/10.53023/p.rasayan-20210619


Liquid crystals (LCs) are a distinct phase of matter whose structural order is intermediate between conventional liquids and solids. They have attracted considerable attention not only because they form the basis of every living being but also due to their ability to show a range of unique properties that are promising from the viewpoints of both fundamental research and applied science. LC phases formed by shapeanisotropic organic molecules such as rod-like and disk-shaped (so-called conventional mesogens) have been investigated exhaustively over the years. Consequently, they have been employed in different technological applications. However, during the last two decades or so, several new mesogenic motifs differing in their shape-anisotropy from conventional LCs have been realized not only to understand the structure-property correlations but also to widen their functional characteristics required for many other non-display applications, including their usage in the organic field-effect transistors, organic photovoltaics, light emitting diodes etc.

Total Synthesis of Hapalindole Alkaloids via Cascade Prins-type Cyclization
Samrat Sahu and Modhu Sudan Maji

Prayogic Rasayan 2021, 5, 37-42

DOI: https://www.doi.org/10.53023/p.rasayan-20210616


This brief highlight described about our recently reported method of cascade Prins-type cyclization method. Structural complexity and interesting biological activity made hapalindole alkaloid an attractive choice to the synthetic organic chemist over the past few decades. Keeping the importance of hapalindole scaffolds in mind, in this line, we recently disclosed a redox-neutral, biomimetic Prins-type cyclization between indole and an aldehyde bearing a terminal ene-promoter. The mild reaction protocol allows incorporation of several key functionalities in the products, and products were isolated with excellent yields and diastereoselectivities. Applying this strategy total synthesis of seven hapalindole alkaloids and formal synthesis of two more related alkaloids were accomplished in a stereodivergent manner in relatively fewer synthetic steps.