A new facile and efficient one-pot three component approach for the preparation of 2, 3, 4-trisubstituted quinolines by (MCM-41)-pyridine catalyzed reaction of easily available substituted isatins and dialkylacetylenedicarboxylates in alcohol has been developed. The (MCM-41)-pyridine nanopowder catalyst has been synthesized and the catalyst has been carefully characterized by various techniques including FT-IR, XRD, HRTEM, EDS, N 2 -adsorption analysis etc. The materials obtained exhibit high surface area and a narrow distribution of mesoporosity.The key features of this methodology are mild reaction conditions, operational simplicity and facile product separation, high to excellent yields, as well as simple catalyst recovery and reusability. The most exciting feature of this cascade reaction is its mechanism involving the unusual ring opening of an isatin moiety, then recyclisation, aromatization followed by esterification. The synthesized substituted quinolines are expected to be used as lead compounds for the development of new drugs.

In this study, a new molecular organic probe has been designed and synthesized by using recyclable, inexpensive and non-toxic polyethylene glycol (PEG-400) as a promoting reaction medium in water under environmentally benevolent conditions. The probe has been explored as a potential chemosensor to detect Al3+ ions using a HEPES buffer (pH = 7.4) solution. Investigations of the fluorescence behaviour of this sensor in DMSO/H2O (2 : 8, v/v) solution displayed a dramatic switch-on response only in the presence of Al3+, while other metal ions, like Li+, Na+, K+, Ag+, Ca2+, Mg2+, Mn2+, Ba2+, Cu2+, Ni2+, Co2+, Fe2+, Zn2+, Cd2+, Hg2+, Pb2+, Sr2+, Fe3+ or Cr3+, have almost no influence on the fluorescence behaviour. Various common anions, such as ClO4-, Cl-, or NO3- in the form of Al3+ salts [e.g. Al(ClO4)3, AlCl3 or Al(NO3)3], had no influence on the fluorescence behaviour of the sensors. The detection limit for Al3+ is in the order of 10-6 M in DMSO/H2O (2 : 8, v/v) HEPES buffer (pH = 7.4) solution. Notably, this is the first report of a dihydroindeno[1,2-b]pyrrole moiety acting as a sensor for the selective detection of Al3+ ions through an off-on fluorescence response. The potential of the probe was also confirmed by employing it for fluorescence bio-imaging with Al3+ on HepG2 cells.

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An ultrasound assisted efficient, expeditious and environmentally benign new methodology for direct access to broad ranges of structurally interesting and pharmacologically significant spiropyrido[2,1‐b][1,3]oxazino compounds based on three component reactions approach via domino 1,4‐dipolar cycloaddition from easily available starting materials in aq. ethanol medium at room temperature (25–30 °C) has been developed. In comparison to that of conventional methods, simple experimental and workup procedure, excellent yields, good functional group tolerance, cleaner reaction profile, use of green solvent are remarkable features of this sonochemical procedure.Furthermore, using of the ultrasound in this methodology leads to the reduction of the reaction times.