Transition-Metal-Free Approach for Z-Vinyl Fluorides by Hydrofluorination of Alkynes bearing SF4 and SF5 Groups

The synthesis of vinyl fluorides plays a crucial role in various scientific disciplines, including pharmaceutical and materials sciences. Herein, we present a direct and stereoselective hydrofluorination method for the synthesis of Z isomers of vinyl fluorides from alkynes containing unexplored SF5 and SF4 groups. Our strategy employed tetrabutylammonium fluoride (TBAF) as a fluorine source. It demonstrates high compatibility with aryls, biaryls, heteroaryls, and tert-alkyl groups, allowing facile incorporation of SF5 and SF4 groups across the triple bond without any transition-metal catalysts. This approach avoids the potential decomposition of the SF5 or SF4 units via coordination with transition metals or acidic protic sources. Remarkably, this transformation proceeded at room temperature without any additional additives, providing the Z isomer of vinyl fluorides in excellent yield and high selectivity. The presence of a water molecule as a hydrate in TBAF is essential for efficient conversion. This methodology opens new avenues for the synthesis of enchanting SF5 - and SF4 -containing fluorinated vinylic scaffolds, thereby providing advanced opportunities for novel drug discovery and fluorinated polymers.

Regio- and Z-Selective Alkyne Hydroamination and Hydrophenoxylation using Tetrafluoro-λ6-Sulfanyl Alkynes under Superbasic, Naked Anion Conditions

Alkyne hydroamination is an effective approach for the production of enamines and enamine-containing N-heterocycles. However, stereoselectivity control is a considerable challenge in this reaction because of the electronic repulsion between an incoming nitrogen lone pair and the alkyne π-system. Herein, we propose a methodology involving β-regio- and Z-selective alkyne hydroamination by using tetrafluoro-λ6-sulfanyl (SF4) alkynes under superbasic, naked anion conditions. The reaction is compatible with a wide variety of N-heterocycles, including indoles, carbazoles, pyrazoles, and imidazoles, and selectively furnishes SF4-linked Z-vinyl enamines with β-regioselectively. Moreover, the method can be extended to the β- and Z-controlled, base-mediated alkyne hydrophenoxylation with phenols to provide SF4-linked Z-vinyl ethers in high yields. As the SF4 unit has attracted attention as a bioisostere for alkynes, p-benzenes, bicyclo[1.1.1]pentyl (BCP) groups, and cubanes in medicinal chemistry, this chemistry represents an effective approach to creating novel drug candidates incorporating SF4-containing molecules.

Unveiling the Three-Component Phosphonylation on Alkynylaldehydes: Toolbox toward Fluorescent Molecules

A regioselective tandem approach for annulated napthyridines/isoquinolines embedded with the phosphine oxide group under mild reaction conditions has been achieved in good to excellent yields. The designed strategy involves the triflate-induced formation of new C sp³-P and C sp²-N bond formation in one pot. This protocol was also well tolerated for the construction of densely functionalized organo-phosphorylated chromenes in good yields. Further, phosphino-derived sulfamethazine and sulfamethoxazole drugs were also successfully synthesized in good yields. The mechanistic studies revealed that the ionic pathway and the formation of regioselective 6-endo dig cyclized products were confirmed through X-ray crystallographic studies. Interestingly, photophysical studies of selectivity selected compounds revealed their stimulating fluorescence properties.

COVID-19-associated psychosis in Indian settings: A retrospective descriptive study

BACKGROUND

The coronavirus-19 (COVID-19) pandemic has affected millions of people across the world since early 2020. Besides the large number of case fatalities, this virus has produced significant health-related sequelae involving multiple systems of the body. As with previous coronavirus infections, this was also found to be associated with various neuropsychiatric symptoms. Psychosis has been uncommon, and the few reported cases across the world have forwarded association with either raised inflammatory markers or the consequences of social isolation.

MATERIALS AND METHODS

This is a retrospective descriptive study of 12 patients, who were admitted with COVID-19 infection and psychosis, between March 2020 and December 2020. Cases of head injury, any neurological or metabolic illnesses, and substance use disorders were excluded.

RESULTS

Cases with psychosis formed only 0.19% of all cases of COVID-19 admissions. All of them were young male and employed. Most of them had abrupt onset of psychosis with confusion, delusions, hallucinations, agitation, and sleep disturbances. Investigations including inflammatory markers (C-reactive protein) and computerized tomography scans were largely normal. Medications used were mainly benzodiazepines and antipsychotics. Most of the cases resolved within the second week, and follow-up after a month did not elicit any residual symptoms in majority. Diagnosis was acute and transient psychotic disorder (about 75%), bipolar affective disorder (2 cases), and schizophrenia (one).

CONCLUSIONS

The major findings included nonreactive inflammatory markers, quick resolution of symptoms, requirement of low doses of antipsychotic drugs, and no long-term sequelae.

Achievements in fluorination using variable reagents through a deoxyfluorination reaction

The application of fluorination reagent for the direct conversion of alcohols and phenols to fluorinated analogues.

Exploring the behavior of the NFSI reagent as a nitrogen source

Applications of the N-fluorobenzenesulfonimide (NFSI) reagent in organic synthesis.

Recent advances in the synthesis of carbazoles from indoles

Synthesis of carbazoles using indoles as precursors through CH activation/annulation.

Palladium meets copper: one-pot tandem synthesis of pyrido fused heterocycles via Sonogashira conjoined electrophilic cyclization

An efficient step-economical tandem approach for the direct synthesis of pyrido fused indole, quinoline, benzofuran and benzothiophene derivatives using a bimetallic Pd/Cu catalytic system has been described. The three component reaction of o-halo aldehydes, alkynes and tert-butylamine leads to the synthesis of biologically active polyheterocycles. The present strategy involves the dual role of tert-butylamine and copper(i) in Sonogashira coupling followed by electrophilic cyclization through imine formation. The chemistry has been validated by X-ray crystallographic studies.

Iodine-mediated synthesis of heterocycles via electrophilic cyclization of alkynes

Syntheses of heterocyclesvia5-exoor 6-endo-digiodocyclizations from alkynes.

Pyrano[4,3-b]quinolines library generation via iodocyclization and palladium-catalyzed coupling reactions

Synthesis of a 80-member library of novel pyrano[4,3-b]quinolines in solution-phase is reported. The key intermediate, 4-iodopyrano[4,3-b]quinolines were synthesized by the electrophilic iodocyclization of corresponding ortho-alkynyl aldehydes in good to excellent yields under mild reaction conditions. Subsequently a diverse set of libraries was generated by employing palladium-catalyzed Suzuki-Miyaura, Heck, and Sonogashira coupling reactions on 4-iodopyrano[4,3-b]quinolines. In this way, a series of structurally different and biologically interesting molecules were obtained. Some of the selected compounds were screened against 3D7 strains of Plasmodium falciparum for antimalarial activity. Suzuki coupling products 6{3} and 6{21} and Heck coupling product 8{12} exhibit promising antimalarial activity.

Prevalence of obesity and overweight in affluent adolescents from Ludhiana, Punjab

The objective was to study the prevalence of obesity among adolescents in public schools of Ludhiana, catering to the affluent segment of population. We selected 1000 students from these schools by random, purposive sampling. Their anthropometry was taken. Students also filled-up a prevalidated questionnaire regarding dietary habits and lifestyle. Overweight/Obesity was defined using age and sex specific Body mass index (BMI) cut off points. Incidence of obesity was 3.4% and overweight was 12.7%. A significantly greater number of boys (15%) were overweight as compared to girls (10%).