Rh(III)-catalyzed (5 + 2)-cycloaddition reactions of ortho-hydroxyethyl phenols with internal alkynes: efficient synthesis of benzoxepines.

An unprecedented (5 + 2)-cycloaddition reaction of ortho-hydroxyethyl phenol and internal alkyne was developed. This Rh(III)-catalyzed reaction provided benzoxepine derivatives which have very high biological significance. A wide range of ortho-hydroxyethyl phenols and internal alkynes were studied to provide the benzoxepines in high yields.

Ru(II)-catalyzed oxidative coupling of sulfoxonium ylides with amines: efficient synthesis of α-ketoamides and indolo[2,1-a]isoquinolines.

The first use of sulfoxonium ylides for the synthesis of α-ketoamides is described via a Ru(II)-catalyzed amidation reaction with amines. The same Ru(II)-catalyzed reaction of sulfoxonium ylides with 2-phenylindoles provided indolo[2,1-a]isoquinolines instead of α-ketoamides.

Recent advances in decarbonylative annulation reactions.

In recent years, decarbonylative annulation reactions have emerged as one of the most efficient routes to construct a variety of important carbocyclic and heterocyclic scaffolds. The main advantages of this type of reaction are, first, the carbonyl compounds are used as the starting materials which are abundant in nature and second, the major by-product of this reaction is carbon monoxide. In the last two decades, various intramolecular and intermolecular decarbonylative annulation reactions have been performed using carbonyl compounds and alkenes/alkynes/arenes/isocyanates etc. as the annulation partners. These reactions are typically performed either in the presence of or in the absence of a metal catalyst. However, these reactions are still in their infancy as a very little progress has been achieved in these reactions. Through this review article, it is attempted to highlight the recent developments on various decarbonylative annulation reactions which ultimately lead to the formation of important structural moieties.

Pd(ii)-Catalyzed regioselective functionalization of antipyrines: synthesis of pyrazolono-maleimides and pyrazolono-quinones.

A Pd(ii)-catalyzed direct functionalization reaction of the 4Csp2-H bond of antipyrine derivatives is reported. This metal-catalyzed reaction of antipyrines with maleimides provided an easy and efficient access to biologically important pyrazolonomaleimides. This catalytic system is also applicable for C-4 functionalization of the antipyrine ring with quinone derivatives.

Correction: Ruthenium(II)-catalyzed decarbonylative and decarboxylative coupling of isatoic anhydrides with salicylaldehydes: access to aryl 2-aminobenzoates.

Correction for 'Ruthenium(II)-catalyzed decarbonylative and decarboxylative coupling of isatoic anhydrides with salicylaldehydes: access to aryl 2-aminobenzoates' by Bidisha R. Bora et al., Org. Biomol. Chem., 2021, 19, 2725-2730, DOI: 10.1039/d1ob00027f.

Ruthenium(ii)-catalyzed decarbonylative and decarboxylative coupling of isatoic anhydrides with salicylaldehydes: access to aryl 2-aminobenzoates.

A ruthenium(ii)-catalyzed coupling reaction of isatoic anhydrides and salicylaldehydes has been developed for the synthesis of 2-aminobenzoates. This reaction proceeds through metal-catalyzed decarbonylation and decarboxylation to afford good yields of aryl 2-aminobenzoates.

Ru(ii)-Catalyzed cascade decarbonylative annulation and dehydrogenative alkenylation reactions: synthesis of phthalides.

A novel Ru(ii)-catalyzed decarbonylative annulation and direct C-H functionalization reaction of phthalic anhydrides with acrylates is reported. This reaction provides an efficient route for the synthesis of 3,7-disubstituted phthalides.

Ruthenium(II)-Catalyzed Dearomatized C-H Activation and Annulation Reaction of Vinylnaphthols with Alkynes: Access to Spiro-Pentacyclic Naphthalenones.

The ruthenium(II)-catalyzed annulation of vinylnaphthols and alkynes is described. The reaction proceeds through C-H activation, dearomatization, and alkyne insertion. This reaction affords spiro-pentacyclic naphthalenones that have biological significance in good yields.

Ruthenium(II)-Catalyzed Synthesis of Spirobenzofuranones by a Decarbonylative Annulation Reaction.

The first decarbonylative insertion of an alkyne through C-H/C-C activation of six-membered compounds is reported. The Ru-catalyzed reaction of 3-hydroxy-2-phenyl-chromones with alkynes works most efficiently in the presence of the ligand PPh3 to provide spiro-indenebenzofuranones. Unlike previously reported metal-catalyzed decarbonylative annulation reactions, in the present decarbonylative annulation reaction, the annulation occurs before extrusion of carbon monoxide.

Carbon-Carbon Bond Cleavage Reaction: Synthesis of Multisubstituted Pyrazolo[1,5-a]pyrimidines.

A new carbon-carbon bond cleavage reaction was developed for the efficient synthesis of multisubstituted pyrazolo[1,5-a]pyrimidines. This base induced reaction of 1,3,5-trisubstituted pentane-1,5-diones and substituted pyrazoles afforded good yields of the pyrazolo[1,5-a]pyrimidines.

Correction: Palladium(II)-catalyzed vinylic geminal double C-H activation and alkyne annulation reaction: synthesis of pentafulvenes.

Correction for 'Palladium(II)-catalyzed vinylic geminal double C-H activation and alkyne annulation reaction: synthesis of pentafulvenes' by Jyotshna Phukon et al., Chem. Commun., 2020, 56, 1133-1136, https://doi.org/10.1039/C9CC09564K.

Hydroxyl-Directed Ru(II)-Catalyzed Synthesis of Fused Dihydrofurans Using 1,4-Dioxane and Sulfoxonium Ylides as Annulating Agents.

An unprecedented annulation reaction is developed for the synthesis of dihydrofuran-fused compounds. In this Ru-catalyzed hydroxyl-group-directed reaction, easily affordable sulfoxonium ylides and 1,4-dioxane were used as the annulating partners. This is the first example of the use of 1,4-dioxane as a methylene source to construct a heterocyclic scaffold. A wide range of dihydrofuran0fused coumarins and naphthalenes were synthesized using this three-component reaction.

Pd(II)-Catalyzed alkyne annulation through allylic isomerization: synthesis of spiro-cyclopentadiene pyrazolones.

The Pd(ii)-catalyzed activation of Csp2-H bond and double alkyne annulation which proceeds via allylic isomerization is reported for the first time. This reaction of antipyrines with alkynes provides an efficient synthetic route for the biologically important spiro-cyclopentadiene pyrazolones. In the presence of Lawesson's reagent, this Pd(ii)-catalyzed annulation reaction affords another spiro-cyclopentadiene pyrazolone which displays very good fluorescence properties.

Nitrofurantoin Susceptibility Pattern in Gram-Negative Urinary Isolates: In Need of Increased Vigilance.

Nitrofurantoin is the first-line drug in the treatment of uncomplicated urinary tract infections (UTIs) and its use has increased exponentially in recent years. Objectives This study aims to determine the susceptibility pattern of nitrofurantoin in gram-negative urinary isolates and to evaluate their bacteriological and epidemiological profile along with co-existing resistance to other important urinary antimicrobials. Material and Methods This was a retrospective study conducted in a tertiary care hospital in New Delhi in which 500 gram-negative bacterial urinary isolates were evaluated. Records of antimicrobial susceptibility were reviewed from July to September 2019. Antimicrobial susceptibility was performed using the Kirby-Bauer disk diffusion method on Mueller Hinton agar and interpreted using CLSI 2019. Test for extended spectrum ß-lactamase (ESBL) producers was done using double disk approximation test. Statistical Analysis Data analysis was performed using the SPSS windows version 25.0 software. Results Out of total 500 isolates, 20.17% (94) isolates were resistant (R) to nitrofurantoin and 9.01% (42) were found to be intermediate (I). Highest resistance was seen in Klebsiella sp. (44.61%) and Escherichia coli (8.12%). About 28.82% of the I/R isolates were of the pediatrics age group and most of the isolates belonged to females (64.69%). High resistance was also seen against ampicillin (92.30%), cefazolin (88.46%), ceftazidime (73.0%), and fluoroquinolones (65.38%). Carbapenemase co-resistance was seen in 57.15% isolates whereas ESBL production was seen in 30.76% of E. coli and 12.06% of Klebsiella sp. Conclusion Increase in multidrug resistance uropathogens along with a near absence of novel oral antibiotics has led to increased consumption of nitrofurantoin since its resistance has increased.

Synthesis of quaternary carbon-centered indolo[1,2-a]quinazolinones and indazolo[1,2-a]indazolones via C-H functionalization.

An unprecedented Ru(ii)-catalyzed Csp2-H bond activation and annulation reaction of phenylindazolones with diaryl-substituted alkynes and dialkyl-substituted alkynes provided efficient routes for the construction of all-carbon quaternary-centered indolo[1,2-a]quinazolinones and quaternary carbon-centered indazolo[1,2-a]indazolones, respectively. The indolo[1,2-a]quinazolinones were fomed via Csp2-H activation, alkyne insertion and a 1,2-phenyl shift. Indazolo[1,2-a]indazolones were formed through a cascade reaction via the formation of exocyclic double bonds containing indolo[1,2-a]quinazolinones.

Perplexity vs Clarity in choosing the right molecular diagnostic techniques for SARS-COV2 detection in Indian setup.

After the havoc created by Spanish flu a century ago, the world is witnessing exactly a similar pandemic situation since the beginning of the year 2020. The unexplained respiratory illness with high morbidity & mortality which started in Wuhan, China and spread across the world was finally termed as COVID-19 disease caused by SARS-CoV-2 and later announced as pandemic by WHO. This novel virus SARS-CoV-2 is a new variant of SARS corona virus with high infectivity and mysterious pathophysiology. The major step towards containment of this pandemic is to scale up the testing for SARS-CoV-2 and thereby isolating and managing the patients at the earliest. Molecular amplification based methods such a Real time Polymerase chain reaction (RT-PCR), CBNAAT and TrueNAT are the most commonly used techniques for detection of SARS-CoV2. To utilize these diagnostic facilities optimally in the management of the suspected COVID 19 patients, it is of utmost importance for the healthcare providers to understand the intricacies related to these technologies. Thus, the technical details along with the pros & cons of these three amplification-based technologies for proper understanding of these diagnostic modalities for SARS COV-2 diagnosis are discussed herewith.

Novel Potent Dopamine-Norepinephrine and Triple Reuptake Uptake Inhibitors Based on Asymmetric Pyran Template and Their Molecular Interactions with Monoamine Transporters.

We have carried out a structural exploration of (2S,4R,5R)-2-(bis(4-fluorophenyl)methyl)-5-((4-methoxybenzyl)amino)tetrahydro-2H-pyran-4-ol (D-473) to investigate the influence of various functional groups on its aromatic ring, the introduction of heterocyclic aromatic rings, and the alteration of the stereochemistry of functional group on the pyran ring. The novel compounds were tested for their affinities for the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) in the brain by measuring their potency in inhibiting monoamine neurotransmitter uptake. Our studies identified some of the most potent dopamine-norepinephrine reuptake inhibitors known to-date like D-528 and D-529. The studies also led to development of potent triple reuptake inhibitors such as compounds D-544 and D-595. A significant influence from the alteration of the stereochemistry of the hydroxyl group on the pyran ring of D-473 on transporters affinities was observed indicating stereospecific preference for interaction. The inhibitory profiles and structure-activity relationship of lead compounds were further corroborated by molecular docking studies at the primary binding sites of monoamine transporters. The nature of interactions found computationally correlated well with their affinities for the transporters.

Comparative evaluation of cost effective extraction free molecular technique for detection of SARS-CoV-2 with reference to standard VTM based RT-qPCR method.

BACKGROUND AND OBJECTIVES: The entire globe is undergoing an unprecedented challenge of COVID-19. Considering the need of rapid and accurate diagnostic tests for SARS-CoV-2, this study was planned to evaluate the cost effective extraction free RT-PCR technique in comparison to the standard VTM based RT-qPCR method. MATERIALS AND METHODS: Paired swabs from nasopharynx and oropharynx were collected for SARS-CoV-2 testing, from 211 adult patients (≥18 years) in VTM and plain sterile tubes (dry swabs). These samples were processed and RT-qPCR was carried out as per standard protocols. RESULTS: 54.5% of the patients were females and 45.5% were males with sex ratio 1:1.19 (M: F). 38.86% were symptomatic, of which fever (86.59%), cough (79.23%) and breathlessness (46.34%) were the most common symptoms. The positivity by VTM based method and index method was 31.27% and 13.27% respectively. Of the 27 inconclusive results from index method, 37.04% were positive, 48.15% were negative by VTM based method. However, in 40 inconclusive results by VTM based method, 90% were negative and rest remained inconclusive by index method. The sensitivity and specificity of the index method were 39.39% and 85.71% respectively. The overall agreement between VTM based method and index method was 49.59% with estimated Kappa value of 0.19. CONCLUSION: VTM based method showed higher sensitivity compared to the index method. The higher positivity by VTM based method, suggests that VTM based method could plausibly be a better detection method of SARS-CoV-2. Still, the index method might add value in a resource limited setups for detection of SARS-CoV-2.

Palladium(ii)-catalyzed vinylic geminal double C-H activation and alkyne annulation reaction: synthesis of pentafulvenes.

The first transition-metal-catalyzed vinylic geminal double C(sp2)-H activation and di-substituted alkyne annulation reaction is reported. This palladium(ii)-catalyzed, amide directed reaction of vinylic compounds with di-substituted alkynes offers an efficient synthetic path to pentafulvenes, which are very important compounds because of their bioactivity and interesting optical properties. A FeCl3-mediated transformation of pentafulvenes to fluorescent cyclopenta[b]quinolines is also developed.