Atul K. Singh

A one-pot regioselective synthetic route to vinyl sulfones from terminal epoxides in aqueous media

A highly efficient LiBr catalysed regioselective synthesis of vinyl sulfones from readily available terminal epoxides and sodium sulfinates in a one-pot procedure using water as a reaction medium is reported. The protocol is adorned with several attributes of green chemistry like recycling of the catalyst, atom-economy and an aqueous medium.

Organocatalysis in synthesis and reactions of epoxides and aziridines

This review systematically describes the synthesis and reactions of epoxides and aziridines using organocatalysis, and includes their reactions like desymmetrization, regioselective nucleophilic ring-opening and cycloaddition with CO2. Based on the various generic modes of activation of organocatalysis, a systematic classification of organocatalysts used for regioselective nucleophilic ring-opening of epoxides and aziridines is given.

NHC-catalysed diastereoselective synthesis of multifunctionalised piperidines via cascade reaction of enals with azalactones.

NHC-catalysed azalactone ring-opening and piperidine ring-closing cascade with α,β-unsaturated aldehydes (enals) in a one-pot operation is reported. The present reaction cascade offers a convenient method for a highly diastereoselective synthesis of multifunctionalised piperidines in excellent yields under mild conditions.

Role of causal and recovery beliefs in the psychological adjustment to a chronic disease

Abstract The main objective of this study was to establish linkages of beliefs about the factors responsible for the disease (causal beliefs) and for recovery from the disease (recovery beliefs) with perceived control and psychological adjustment to a chronic disease. Seventy hospitalized male, Hindu, chest tuberculosis patients were interviewed. The mean ratings on causal factors (Gods will and Karma) and on recovery factors (doctor and God) were found to be high. In general, attribution to external causes (others carelessness and family conditions) and beliefs in cosmic recovery factors (God and fate) had negative correlations with the psychological adjustment. Again, perceived control over the disease was linked with better adjustment. A cultural difference hypothesis was proposed to explain coping with a chronic disease.

Synergistic effect of stromelysin-1 (matrix metalloproteinase-3) promoter (-1171 5A->6A) polymorphism in oral submucous fibrosis and head and neck lesions

BackgroundMatrix metalloproteinases (MMPs) are enzymes that degrade all the components of extra cellular matrix and collagen. Various types of MMPs are known to be expressed and activated in patients with oral submucous fibrosis (OSMF) as well as head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to asses the association of the single nucleotide polymorphism (SNP) adenosine insertion/deletion polymorphism (-1171 5A->6A) in the MMP-3 promoter region in these lesions.MethodsMMP-3 SNP was genotyped by polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) analysis in a case control study consisting of 362 participants; 101 cases of OSMF, 135 of HNSCC and 126 controls, compared for age, sex and habits. ROC distribution was plotted to assess the contributions of genetic variation in MMP-3 genotypes with relation to age.ResultsAnalysis of MMP 3 (-1171 5A->6A) polymorphism revealed the frequency of 5A allele in OSMF, HNSCC and controls to be 0.15, 0.13 and 0.07, respectively. A significant difference was found in 5A genotype frequency between OSMF (5A genotype frequency = 0.15, p = 0.01, OR = 2.26, 95% CI = 1.22-4.20) and in controls (5A genotype frequency 0.07) as well as HNSCC (5A genotype frequency 0.13, p = 0.03,95%CI = 1.06-3.51) and controls (5A genotype frequency = 0.07) In this study, 5A genotype had greater than two fold risk for developing OSMF (OR = 2.26) and nearly the same in case of HNSCC (OR = 1.94) as compared to controls. In patients with OSMF as well as HNSCC, the ROC analysis between the MMP-3 genotype and age, 6A/6A allele was found to be significant in patients both over and under 45 years of age; while the 5A/5A carrier alleles showed an association only in patients less than 45 years of age.ConclusionsThis study concluded that the expression of MMP-3 genotype associated with the 5A alleles, it may have an important role in the susceptibility of the patients to develop OSMF and HNSCC.

Retracted article: Convenient access to strained trisubstituted 2-azetines from enals and chloramine-T in aqueous media

We, the named authors, hereby wholly retract this Green Chemistry article due to subsequent realisation of the incorrect assignment of the structures in the paper. n Signed: Atul K. Singh, Ruchi Chawla and Lal Dhar S. Yadav, February 2013Retraction endorsed by Sarah Ruthven, Managing Editor, Green Chemistry

Provenance of Bar-Top Sediments at Tons River near Allahabad

The bar-top sediments at the Tons river deposited mainly from the suspension current during waning stage condition of river are collected to study their provenance on the basis of clay mineralogy, heavy minerals and magnetic properties. The clay mineral assemblages in samples predominantly consist of illite, with minor amounts of kaolinite, smectite and chlorite. The clay minerals are contributed due to (i) weathering and decomposition of shales, argillaceous limestones and pyroclastic deposits of upper Vindhyan Groups and (ii) weathering and erosion of Banda plain of Gangetic alluvium. The low ZTR index for the studied samples indicates poor sediment maturity, rapid erosion in the source region and short transportation of detritus. The transparent heavy mineral assemblages in the sediment samples predominantly consist of garnet, with minor amounts of tourmaline, zircon, hornblende, enstatite, hypersthene, rutile, tremolite, kyanite, sillimanite, andalusite, chlorite, epidote, wollastonite, and staurolite. The heavy minerals are dominantly angular to sub-angular with some rounded to sub-rounded grains. The rounded grains indicate multicyclicity and derivation fromVindhyan sandstones. The angular grains are either contributed due to erosion of primary rocks of Bundelkhand gneissic complex and or various Gangetic alluviums. The magnetic properties from sediment samples indicate that the antiferromagnetic minerals (illite, chlorite and smectite) are more concentrated in clay sized particles and it also indicated mixed source rocks for the bar-top sediment of Tons river.