Gavin O Jones

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We report efficient syntheses of axially chiral biaryl amides in yields ranging from 80-92%, and with enantioselectivity in the range 88-94% ee employing an asymmetric Suzuki-Miyaura process with Pd(OAc)(2) and KenPhos as ligand. These studies demonstrate that electron-rich and electron-deficient o-halobenzamides can be efficiently coupled with(More)
The transition states and activation barriers of the 1,3-dipolar cycloadditions of azides with cycloalkynes and cycloalkenes were explored using B3LYP density functional theory (DFT) and spin component scaled SCS-MP2 methods. A survey of benzyl azide cycloadditions to substituted cyclooctynes (OMe, Cl, F, CN) showed that fluorine substitution has the most(More)
Density functional theory (B3LYP) calculations on the transition states for the Huisgen 1,3-dipolar cycloadditions of phenyl azide with acetylene, cyclooctyne, and difluorocyclooctyne are reported. The low activation energy of the cyclooctyne "strain-promoted" cycloaddition (DeltaE = 8.0) compared to the strain-free acetylene cycloaddition (DeltaE = 16.2)(More)
Nitrogen-based thermoset polymers have many industrial applications (for example, in composites), but are difficult to recycle or rework. We report a simple one-pot, low-temperature polycondensation between paraformaldehyde and 4,4'-oxydianiline (ODA) that forms hemiaminal dynamic covalent networks (HDCNs), which can further cyclize at high temperatures,(More)
Combined experimental and computational studies have been performed on the mechanism of formation of poly(hexahydrotriazine) and hemiaminal dynamic covalent network (PHT and HDCN) thermosetting polymers from the reactions of diamines with formaldehyde (Science 2014, 344, 732-735). Results suggest that these polymers are formed by a mechanism involving the(More)
Computational investigations of ligand-directed selectivities in Ullmann-type coupling reactions of methanol and methylamine with iodobenzene by beta-diketone- and 1,10-phenanthroline-ligated Cu(I) complexes are reported. Density functional theory calculations using several functionals were performed on both the nucleophile formation and aryl halide(More)
Dynamic covalent materials are stable materials that possess reversible behaviour triggered by stimuli such as light, redox conditions or temperature; whereas supramolecular crosslinks depend on the equilibrium constant and relative concentrations of crosslinks as a function of temperature. The combination of these two reversible chemistries can allow(More)
The activation enthalpies for the reactions of cyclopentadiene with ethylene, acrylonitrile, fumaronitrile, maleonitrile, vinylidene cyanide, tricyanoethylene, and tetracyanoethylene have been computed with the Hartree-Fock quantum mechanical method and a variety of density functionals (B3LYP, BPW91, and MPW1K) and compared to classic experimental data(More)
Experimental and computational investigations of the zwitterionic ring-opening polymerization (ZROP) of δ-valerolactone (VL) catalyzed by the N-heterocyclic carbenes (NHC) 1,3-diisopropyl-4,5-dimethyl-imidazol-2-ylidene (1) and 1,3,4,5-tetramethyl-imidazol-2-ylidene (2) were carried out. The ZROP of δ-valerolactone generates cyclic poly(valerolactone)s(More)
Computational investigations with density functional theory (DFT) have been performed on the N-heterocyclic carbene (NHC) catalyzed ring-opening polymerization of ε-caprolactone in the presence and in the absence of a methanol initiator. Much like the zwitterionic ring opening (ZROP) of δ-valerolactone which was previously reported, calculations predict(More)