Sauradip Chaudhuri

Environmentally friendly procedure for the aqueous oxidation of benzyl alcohols to aldehydes with dibromodimethylhydantoin (DBDMH) and cyclodextrin: Scope and mechanistic insights

ABSTRACT Reported herein is an environmentally friendly procedure for the oxidation of benzyl alcohols to aldehydes using an inexpensive, commercially available reagent, 1,3-dibromo-5,5-dimethylhydantoin (DBDMH), and a variety of cyclodextrin additives under fully aqueous solvent conditions. This reaction proceeds with moderate to good yields for a broad scope of benzyl alcohol substrates, with the cyclodextrin acting to enhance the desired reactivity and limit undesired aromatic bromination side products. The reported experiments provide substantial mechanistic insight that will drive further reaction optimization and have broad-reaching applications. GRAPHICAL ABSTRACT

A highly versatile fluorenone-based macrocycle for the sensitive detection of polycyclic aromatic hydrocarbons and fluoride anions

Reported herein is the high yielding synthesis of a new fluorenone-based triazolophane and its sensing capabilities for polycyclic aromatic hydrocarbons (PAHs) and fluoride anions. Fluorescence, UV/Vis and 1H NMR spectroscopy results showed the triazolophane has a high sensitivity for selected PAHs and binds the fluoride anion in a 2 : 1 stoichiometry via C–H hydrogen bonding with the triazole and fluorenone protons.

Synthetic Access to Functionalized Dipolarophiles of Lewis Basic Complexant Scaffolds through Sonogashira Cross-Coupling

Soft Lewis basic complexants that facilitate selective removal of discrete ions resident in spent nuclear fuel can decrease repository volume and radiotoxicity and are of significant interest. Optimization of chelation efficacy is predicated on modular access to synthons to rapidly evaluate structure-activity relationships. The following work highlights efficient access to functionalized synthons for use as potential dipolarophiles in subsequent cycloaddition processes via Sonogashira coupling of 3-(6-bromo-pyridin-2-yl)-[1,2,4]triazine scaffolds. The 41 examples explored during method development evaluated electrophile and nucleophile diversity affording the desired coupled products in 31-96% isolated yield. Method optimization, substrate scope, a scale-up reaction, and downstream product functionalization are reported herein.

Array-based detection of isomeric and analogous analytes employing synthetically modified fluorophore attached β-cyclodextrin derivatives

Reported herein is a sensitive and selective array-based sensing strategy based on differential interactions with three supramolecular cyclodextrin–fluorophore sensors. Each interaction results in a distinct fluorescence modulation response, and linear discriminant analyses of these responses results in 100% successful classification of three classes of isomeric analytes and two classes of analogous analytes. Calculated limits of detection for this system are at or near literature-reported levels of concern.