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A benzothiazole-based receptor conjugated with an imidazolium cation, receptor N1, was synthesized. Receptor N1 is capable of selectively binding Hg(II) in the presence of other metal ions in water, with a large enhancement in fluorescence intensity at 380 nm via a PET mechanism. The resulting Hg(II) complex of receptor N1 showed a selective ratiometric response upon addition of Br− ions. The Hg(II) complex of receptor N1 was used to determine the concentration of Br− ions in the presence of other anions, with a detection limit of 22 nM. 1H NMR studies showed that the imidazolium hydrogen in the Hg(II) complex of receptor N1 participates in the recognition of Br− ions. In the absence of Hg(II), receptor N1 did not recognize Br− ions.

We synthesized a dinuclear Cu(II) paddle-wheel complex R1 containing a benzimidazolium ligand and explored using it as a fluorescence turn-ON sensor for detecting phosphates in water. The sensor exhibited both fluorescence and electrochemical responses to phosphates with high selectivity and sensitivity over other anions, which makes it useful for the detection of harmful organophosphates.

A series of tricyclic dihydropyrimidine derivatives were synthesized using a one-pot, three-component Traube–Schwarz reaction in the presence of catalyst Zn(ClO4)2·6H2O. All the purified compounds were evaluated for their in vitro anticancer activity against three different cancer cell lines such as prostate cancer cells (PC3), lung cancer cells (NCI-H1299) and colon cancer cells (HCT116). In vitro DNA-intercalation ability of the compounds was investigated by UV–vis absorption spectroscopy, showing the insertion of compound into the DNA base pairs and a strong interaction with the DNA double helix.

An azo dye-coupled benzimidazole-based receptor 1 was synthesized and investigated as a receptor for metal ions in semi-aqueous medium. The receptor recognizes Cu2+ with high selectivity over other metal ions. The resultant complex 1·Cu2+ was found to selectively bind oxalic acid via counter ion displacement.

A benzthiazole-based multifunctional chemosensor was designed with siderophores like binding sites for recognition of Fe3+ and both hydrogen bond donor and acceptor binding sites for oxyanion HSO 4 − . The sensor recognizes Fe3+ selectively through enhancement of fluorescence emission intensity at 440 nm and recognizes HSO 4 − through a bathochromic shift in UV–vis spectra from 315 nm to 365 nm with clear isosbestic points at 345 nm and 395 nm. The recognition of both Fe3+ and HSO 4 − is free from the interference from the other cations and anions, respectively.

A benzimidazole-based receptor that selectively recognized Cr3+ without interference from other metal ions was synthesized in this study. The resultant Cr-complex recognized HSO4− and F− via two approaches. HSO4− ions bound to the metal center, causing changes in the fluorescent spectra at different wavelengths, whereas F− ions displaced Cr3+, thereby switching ON the fluorescent spectra at the same wavelength.

An efficient method for the asymmetric synthesis of highly optically pure 2-substituted piperidines and 6-substituted piperidine-2-ones from aldehydes was developed by a sequence of enantioselective hydrazone allylation and ring closing metathesis. This method was found to be effective for a variety of substrates, showing substrate generality. The method's synthetic utility was illustrated in concise synthesis of the alkaloid (R)-(−)-coniine.

A new benzimidazole-based receptor was developed with potential functional groups for excited state proton transfer (ESPT) through keto–enol tautomerism. The enol form of the receptor selectively recognizes Zn2+, allowing it to be used as a ratiometric fluorescence sensor in DMSO/CH3CN (1:9, v/v). The binding event triggers a blue-shifted band through the modulation of charge transfer transitions. The sensor is applicable for recognizing Zn2+ in the cytoplasm of Saccharomyces cerevisiae.

We synthesized an imine-linked, benzimidazole-based chemosensor that can be used for chromogenic recognition of Mg 2+ and fluorescent recognition of Cr 3+ . The chemosensor shows sensitive, selective, and ratiometric recognition of Cr 3+ through concurrent quenching at one wavelength and enhancement of fluorescence intensity at another wavelength. It can also be used to detect Mg 2+ via UV–vis absorption spectroscopy. DFT calculations support these phenomena. The sensor can be used to strain microbe cells without breakage.

We synthesized a novel receptor with a unique combination of sp2 nitrogen (–CH N–) and carbonyl groups from amide linkages. These two moieties are judiciously incorporated into the receptor design such that these sites simultaneous binding a metal ion may generate a stable five-member ring. The receptor has been used to selectively detect Zn2+ through changes in the fluorescence spectra. Upon Zn2+ binding with the receptor, the fluorescence band shifted to enhance fluorescence intensity, allowing ratiometric determination of Zn2+ concentration.

A convenient and efficient method was developed for the synthesis of alkyl phenyl selenides, sulfides, and selenoesters in one-pot reaction by using indium metal. The reaction showed the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides. For the reaction of primary and secondary alkyl iodides and bromides, the yields of selenides were improved by the addition of a catalytic amount of iodine.

p-tert-Butylcalix[4]arene-based dipodal receptor has been synthesized in cone conformation. The binding affinity of this receptor was evaluated with some aliphatic diacetates such as malonate, succinate, glutarate, adipate, pimelate, and suberate in CH3CN. The receptor has the highest binding affinity for pimelate by making a 1:1 complex. This receptor was used to estimate pimelate in the presence of other dicarboxylates.

We synthesized a novel colorimetric anion chemosensor bearing benzimidazole motifs as recognition sites in the pods of the receptor. The addition of tetrabutylammonium salts of F − or AcO − to the solution of receptor caused dramatic color changes from colorless to yellow, which was clearly visible to the naked eye. The receptor showed no significant changes on addition of other anions such as Cl − , Br − , I − , NO 3 − , and H 2 PO 4 − .

Various thionoesters and thionolactones are readily reduced into the corresponding ethers in high isolated yields by radical desulfurization with organotin hydrides and Et 3 B under mild reaction conditions.

Various thionocarbonates and xanthates of alcohols and bis -xanthates of vic -diols are readily deoxygenated to the corresponding hydrocarbons or olefins, while bromides and iodides are dehalogenated with diphenylphenylsilane in good yield.

Thionocarbonates and xanthates of primary and secondary alcohols, as well as bis-xanthates of vic-diols are readily deoxygenated to the corresponding hydrocarbons or olefins with phenylsilane, triphenylsilane, and triethylsilane in good yield.

Novel radical-chain deoxygenations of primary alcohols are described. The alcohols are acylated with the reagents pentafluorophenyl chlorothionoformate, 2,4,6-trichlorophenyl chlorothionoformate and 4-fluorophenyl chlorothionoformate and the intermediate thionocarbonates are deoxygenated with tributyltin hydride, triphenylsilane, diphenylsilane or phenylsilane in high-yielding reactions.