@article { ISI:000254446000024, title = {Pre-organization-mediated macrocylization: efficient synthesis and structural investigations of BINOL-m-phenylenediamine-derived macrocycles}, journal = {Tetrahedron Letters}, volume = {49}, number = {13}, year = {2008}, month = {MAR}, pages = {2139-2142}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

This letter describes a serendipitous discovery of an efficient synthetic route to BINOL-m-phenylenediamine-derived macrocycles. These macrocycles are quickly accessible in an one-pot procedure by the direct condensation of (R) and (S) BINOL bis-acids with suitably substituted m-phenylenediamine analogs. Structural investigations by single crystal X-ray crystallography and solution-state NMR studies provided convincing evidence of their intramolecular hydrogen bonding arrangement and rigid structural architecture. The striking feature of these macrocycles is their ready accessibility in optically pure form coupled with their ease of synthesis. (C) 2008 Elsevier Ltd. All rights reserved.

}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2008.01.116}, author = {Srinivas, Deekonda and Gonnade, Rajesh G. and Rajamohanan, P. R. and Sanjayan, Gangadhar J.} } @article { ISI:000332485000048, title = {Probing the folding induction ability of orthanilic acid in peptides: some observations}, journal = {RSC Advances}, volume = {4}, number = {25}, year = {2014}, month = {JAN}, pages = {13018-13025}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

This paper describes the ability of orthanilic acid (2-aminobenzenesulfonic acid, (S)Ant) to promote folding when introduced in a peptide sequence. Three peptide sequences, containing orthanilic acid (SAnt) with a sulfonamide moiety in the turn segment, have been synthesized in the solution phase using suitable coupling agents, and their structural aspects investigated using NMR and X-ray crystallographic studies. Solid- and solution-state conformational analyses reveal that the peptide sequences containing orthanilic acid in their backbone exist in a folded conformation featuring long-range 15-membered ring H-bonding.

}, issn = {2046-2069}, doi = {10.1039/c3ra47039c}, author = {Roy, Arup and Kotmale, Amol S. and Gawade, Rupesh L. and Puranik, Vedavati G. and Rajamohanan, P. R. and Sanjayan, Gangadhar J.} } @article { ISI:000351325200008, title = {Pyrazine-based organometallic complex: synthesis, characterization, and supramolecular chemistry}, journal = {Inorganic Chemistry}, volume = {54}, number = {6}, year = {2015}, month = {MAR}, pages = {2543-2550}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The design, synthesis, and characterization of a new pyrazine-based ditopic platinum(II) organometallic complex are reported. The molecular structure of the organoplatinum pyrazine dipod was determined by single-crystal X-ray crystallography. The potential utility of this organometallic ditopic acceptor as a building block in the construction of neutral metallasupramolecular macrocycles containing the pyrazine motif was explored. Pyrazine motifs containing supramolecules were characterized by multinuclear NMR (including H-1 DOSY), mass spectrometry, and elemental analysis. The geometry of each supramolecular framework was optimized by employing the PM6 semi-empirical molecular orbital method to predict its shape and size. The ability of the pyrazine-based organoplatinum complex to act as a host for nitroaromatic guest (2,4-dinitrotoluene and PA) molecules was explored by isothermal titration calorimetry (ITC). The binding stoichiometry and thermodynamic parameters of these host guest complexation reactions were evaluated using ITC. Theoretical calculations were performed to obtain insight into the binding pattern between the organometallic host and nitroaromatic guests. The preferable binding propensity of the binding sites of complex 1 for both nitroaromatics (PA and 2,4-dinitrotoluene) determined by molecular simulation studies corroborates well with the experimental results as obtained by ITC experiments.

}, issn = {0020-1669}, doi = {10.1021/ic502581x}, author = {Bhowmick, Sourav and Chakraborty, Sourav and Das, Atanu and Rajamohanan, P. R. and Das, Neeladri} }