https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

In 1893, P. Biginelli reported the synthesis of functionalized 3, 4-dihydropyrimidin-2(1H)-ones (DHPMs) via three-component condensation reaction of an aromatic aldehyde, urea, and ethyl acetoacetate. In the past decade, this long-neglected multicomponent reaction has experienced a remarkable revival, mainly due to the interesting pharmacological properties associated with this dihydropyrimidine scaffold. In this Account, we highlight recent developments in the Biginelli reaction in areas such as solid-phase synthesis, combinatorial chemistry, and natural product synthesis.

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Recent advances in the Biginelli dihydropyrimidine synthesis. New tricks from an old dog.

Utilisation of 1,3‐Dicarbonyl Derivatives in Multicomponent Reactions

Recent developments in the chemistry of enaminones

Multicomponent reactions have gained significant importance as a tool for the synthesis of a wide variety of useful compounds, including pharmaceuticals. In this context, the multiple component approach is especially appealing in view of the fact that products are formed in a single step, and the diversity can be readily achieved simply by varying the reacting components. The eco-friendly, solvent-free multicomponent approach opens up numerous possibilities for conducting rapid organic synthesis and functional group transformations more efficiently. Additionally, there are distinct advantages of these solvent-free protocols since they provide reduction or elimination of solvents thereby preventing pollution in organic synthesis “at source”. The chemo-, regio- or stereoselective synthesis of high-value chemical entities and parallel synthesis to generate a library of small molecules will add to the growth of multicomponent solvent-free reactions in the near future. In this review we summarized the results reported mainly within the last 10 years. It is quite clear from the growing number of emerging publications in this field that the possibility to utilize multicomponent technology allows reaction conditions to be accessed that are very valuable for organic synthesis. Therefore, diversity oriented synthesis (DOS) is rapidly becoming one of the paradigms in the process of modern drug discovery. This has spurred research in those fields of chemical investigation that lead to the rapid assembly of not only molecular diversity, but also molecular complexity. As a consequence multi-component as well as domino or related reactions are witnessing a new spring.

/pdf/recent-developments-in-solvent-free-multicomponent-reactions-4ugdax2te0.pdf

Recent developments in solvent-free multicomponent reactions: a perfect synergy for eco-compatible organic synthesis

A synthetic entry into fused pyran derivatives through carbon transfer reactions of 1,3-oxazinanes and oxazolidines with carbon nucleophiles

An expedient protocol of the Biginelli dihydropyrimidine synthesis using carbonyl equivalents

Isolation of Eleven New Spinochromes from Echinoids of the Genus Echinothrix

We successfully demonstrate 40 GB/s 8 channels’ Dense Wavelength Division Multiplexing (DWDM) over free space optical (FSO) communication system. Each channel is transmitting 5 GB/s data rate in downstream separated by 0.8 nm (100 GHz) channel spacing with 1.8 GHz filter bandwidth. DWDM over FSO communication system is very effective in providing high data rate transmission with very low bit error rate (BER). The maximum reach of designed system is 4000 m without any compensation scheme. The simulation work reports minimum BER for Return-to-Zero (RZ) modulation format at different channels 1, 4, and 8 are found to be , , and at 4000 m distance, respectively. Sharp increase in BER occurs if data rate and distance increase up to 10 GB/s and 5000 m.

/pdf/performance-investigation-of-40-gb-s-dwdm-over-free-space-2ckewfjjk1.pdf

Performance Investigation of 40 GB/s DWDM over Free Space Optical Communication System Using RZ Modulation Format

Carbon transfer reactions of functionalized oxazolidines and their open chain enamine tautomers to enamine nucleophiles. A facile synthesis of substituted pyridines and ring annulated derivatives

Harjit Singh

Papers

A synthetic entry into fused pyran derivatives through carbon transfer reactions of 1,3-oxazinanes and oxazolidines with carbon nucleophiles

An expedient protocol of the Biginelli dihydropyrimidine synthesis using carbonyl equivalents

Isolation of Eleven New Spinochromes from Echinoids of the Genus Echinothrix

Performance Investigation of 40 GB/s DWDM over Free Space Optical Communication System Using RZ Modulation Format

Carbon transfer reactions of functionalized oxazolidines and their open chain enamine tautomers to enamine nucleophiles. A facile synthesis of substituted pyridines and ring annulated derivatives