No abstract

A Pd(II)-catalyzed highly regioselective γchalcogenation, thioarylation, and selenoarylation of aliphatic carboxylic acids has been demonstrated. The present protocol provides a direct access to make structural modifications of αamino acids such as valine, isoleucine, and tert-leucine with high diastereoselectivity (up to 52:1). Sequential heterobifunctionalizations have been carried out at γ-sp 3 C−Hs, resulting in desymmetrization of quaternary centers. The applicative potential of the chalcogenated products was exhibited by using them as precursors for the synthesis of the biologically relevant benzothiepinone moiety. Preliminary studies were carried out to gain insights into the mechanism.

High yield amination of GO showing improved dispersion in epoxy resin.

All-atom molecular dynamics simulations are performed on pure monomer and trimer of polycarbonate and their mixtures with different molecular weight percentages of embedded single walled carbon nanotubes at different temperatures to study the structural and dynamical properties of the composite system. The diffusion behaviors of monomer, trimer of polycarbonate and carbon nanotubes in composite matrices are investigated and compared with pure matrices in details. Both structural and dynamical properties indicate the weak interaction between the nanotubes and matrix molecules. The high tendency of nanotubes to form bundles is observed during simulation. The bundle formation free energy has been calculated from the potential of mean force calculations. The mechanism and energetics of bundle formation is explored in the atomistic scale. The formation of the carbon nanotube bundle is a favorable process in the oligomeric polycarbonate matrix.