Dimerization of 3-substituted 2-oxindoles has been developed under a mild electrochemical condition, avoiding toxic chemical oxidants and metal by-products. This methodology forms a C­(sp3)–C­(sp3) bond at the pseudobenzylic position of two partners of 2-oxindoles with a broad substrate scope. These dimeric structural motifs are important building blocks for the total synthesis of pyrroloindoline alkaloids. Furthermore, this work demonstrates in-depth mechanistic insights employing electrochemistry, which suggests a stepwise one proton transfer (PT) and two electron transfer (ET) processes. Most significantly, reaction rate acceleration has been demonstrated by exploiting the base-assisted proton-coupled electron transfer (PCET) pathway. Hence, this work brings a new dimension in the field of electro-organic synthesis with the help of nature’s favorite kinetic route, i.e., PCET, to lower the kinetic barrier.

The Fujiwara–Moritani reaction using electric current is a powerful tool for the olefination of arenes by Pd-catalysed C–H activation.

An efficient electrochemical strategy has been developed for the total synthesis of dimeric hexahydropyrrolo[2,3-b]indole alkaloids. In particular, oxidative dimerization of 3-alkyl 2-oxindoles was developed for this study. A detailed CV...

Dimerized 3-substituted 2-oxindoles are essential building blocks for the total synthesis of alkaloids. Herein, three different types of 3-substituted-2-oxindoles were dimerized with a total of 41 examples employing TEMPO as a redox mediator and TEMPO+ as an in situ generated electrocatalyst using control potential electrolysis at an applied potential of only 0.8 V versus a Ag/Ag+ nonaqueous reference electrode. These reactions did not yield any product formation in the absence of TEMPO, keeping other experimental conditions the same. Two-electron- and one-electron-transfer pathways were operational depending on the oxidation potentials of 2-oxindoles. 3-Carboxylate-2-oxindoles having a lower oxidative energy barrier for a two-electron-transfer pathway followed a hydride-transfer mechanism to generate a carbocation, which thereafter reacted with the enol form of oxindole to produce dimerized 2-oxindoles. On the other hand, 3-alkyl-2-oxindoles and 3-alkylcarboxylate-2-oxindoles had significantly higher oxidative energy barrier compared to 3-carboxylate-2-oxindoles and followed the one-electron-transfer pathway to generate a radical species for dimerization. The two-electron transfer pathway was significantly faster compared to the one-electron transfer pathway, evident from reaction time (15 min vs 1 h 20 min or longer), which was due to a faster second-order rate constant for the two-electron transfer pathway (1.2 M–1 s–1) compared to the one-electron transfer pathway (0.29 M–1 s–1). Furthermore, four aspects of transforming greener electro-organic synthesis have been demonstrated. They are as follows: (a) electron-transfer rate measurement as an alternative method for synthesis optimization instead of lengthy product isolation, (b) prevention of electrode passivation employing electrocatalysis routes, (c) recovery of the electrolyte, and (d) mild reaction conditions employing control potential electrolysis. Finally, an efficient electrochemical oxidation strategy has been demonstrated for the total synthesis of a dimeric hexahydropyrrolo[2,3-b]indole alkaloids, (±)-chimonanthine (I) and (±)-folicanthine (II).

Objectives: This study aimed to determine the seroprevalence of brucellosis among pigs of commercial farms in Chitwan district of Nepal. Methods: This cross sectional prospective study was conducted among 100 pigs of commercial farms located in western region of Chitwan district of Nepal. Blood sample was collected from each pig by the trained veterinarians and serum was extracted. Each serum sample was processed for Rose Bengal plate test (RBPT) and ELISA for the detection of Brucella spp. Data was analyzed using SPSS software version 21.0 and a p-value of less than 0.05 was considered as significant. Results: Prevalence of brucellosis in pigs was found to be 15% (15/100) by RBPT and 10% (10/100) by ELISA. There was statistically insignificant difference (p=0.98) in gender wise prevalence of brucellosis among pigs. Younger pigs below one year of age were more susceptible to brucellosis than the older pigs. Landrace breed showed more positive test results compared to other breeds. Conclusion: Pigs can be the potential source of transmission of brucellosis to humans. Considering the high economic loss on livestock sector and possible transmission to humans, awareness program and appropriate control strategies is warranted. Breed and age factors should be considered while adopting the control measures of brucellosis among pigs.