Metal-free thiolation of sulfonyl hydrazone with thiophenol: synthesis of 4-thio-chroman and diarylmethyl thioethers.

A simple, efficient, and transition metal-free approach was developed for accessing 4-thio-substituted chroman and diarylmethyl thioethers from sulfonyl hydrazones. This protocol provides straightforward access to a class of diarylmethane derivatives with good to excellent yields. This operationally simple protocol exhibited good tolerance for labile functional groups, providing biologically relevant chemical libraries. This safe and feasible route is applicable to the large-scale synthesis of 4-thio-substituted chromans, which are of great synthetic interest because of their further reaction potential.

A Synthetic Overview of Benzoxazines and Benzoxazepines as Anticancer Agents.

Benzoxazines and benzoxazepines are nitrogen and oxygen-containing six and seven-membered benzo-fused heterocyclic scaffolds, respectively. Benzoxazepines and benzoxazines are well-known pharmacophores in pharmaceutical chemistry, which are of significant interest and have been extensively studied because of their promising activity against various diseases including their wide range of anticancer activity. Several reports are known for synthesizing benzoxazine and benzoxazepine-based compounds in the literature. Herein this review provides a critical analysis of synthetic strategies towards benzoxazines and benzoxazepines along with various ranges of anticancer activities based on these molecules that have been reported from 2010 onwards. This review also focuses on the structure-activity relationship of the benzoxazine and benzoxazepine scaffolds containing bioactive compounds and describes how the structural modification affects their anticancer activity.

Transition-Metal-Free Multicomponent Approach to the Regioselective Synthesis of Highly Substituted N-Alkylpyrazoles.

An efficient transition-metal-free multicomponent approach to the regioselective synthesis of highly substituted N-alkylpyrazoles through 1,6-addition of pyrazole (in situ generated from α,ß-unsaturated aldehyde and hydrazide) to para-Quinone Methides has been developed. The N-alkylpyrazole containing triarylmethanes having several heteroaryl rings (quinoline, pyridine, thiophene) at the central methine carbon atom was developed. This chemical process may be used for large-scale synthesis and provides a novel way to produce triarylmethanes with diverse functional groups.

Transition metal-free reductive coupling of allylic sulfonylhydrazones with aryl boronic acids for C(sp3)-C(sp2) bond formation.

The reductive coupling between allylic sulfonylhydrazones and aryl boronic acids gives 1,3-diarylpropene systems with good to excellent yields. Simple reaction conditions, high yields, and good functional group tolerance are the salient features of this reaction which takes place without using any transition-metal catalysts and an inert atmosphere. The substituents on aryl boronic acid or allylic sulfonylhydrazone play a role in the isomerization of the double bond. The 3,3-diphenylacrylaldehyde derived allylic sulfonylhydrazone gives almost exclusively a single isomer.

Reactivity vs. selectivity of quinone methides: synthesis of pharmaceutically important molecules, toxicity and biological applications.

Quinone methides (QMs) are considered to be highly reactive intermediates because of their aromatization both in chemical and biological systems. Being highly accessible, quinone methides (QMs) have been widely exploited and their concurrent use has been manifested for the synthesis of tertiary and quaternary carbon centers of bioactives, drugs and drug-like molecules. In this feature article, the synthetic routes, structure-reactivity relationships and synthetic applications of quinone methides are discussed. Formation of the intermediates during bioactivation of different chemical entities and possible chemical manifestations leading to their toxicity in biological systems are also covered.

The quality of groundwater for certain chemicals in military fields in Ankara.

OBJECTIVE: The goal of this study was to determine the quality of groundwater for certain chemicals from all wells for the military units in Ankara (the capital city of Turkey) to evaluate special situations like a nuclear, biological, and chemical attack. METHOD: The quality of underground water has been evaluated chemically by examining 34 different water specimens. Various chemical parameters and heavy metals have been assessed in these samples by using an ion meter and atomic absorption spectrophotometer. RESULTS: Nitrate and chloride have been assessed at a higher rate with the levels exceeding maximum contaminant levels. Mercury, arsenic, aluminum, iron, conductivity, and salinity have also had levels exceeding maximum contaminant levels for each of them according to the levels set by the World Health Organization. CONCLUSION: This study has given us some powerful clues that underground water in Ankara is at a growing risk to be contaminated mainly with nitrate and chloride. Although more detailed investigations are necessary for a better evaluation, it is clear that preventive measures should be implemented or improved.