Chiral <i>N</i>-Acyloxazolidines: Synthesis, Structure, and Mechanistic Insights
作者:Martín Ávalos、Reyes Babiano、Pedro Cintas、José L. Jiménez、Mark E. Light、Juan C. Palacios、Esther M. S. Pérez
DOI:10.1021/jo702149m
日期:2008.1.1
cis-configured derivative. Both isomers can also exist as rotational conformers (E,Z) as a consequence of the restricted rotation around the N-acetyl bond. The barriers to rotation have been determined by variable-temperature experiments. Overall, this transformation most likely involves the intermediacy of a chiral iminium ion, which has been documented in the synthesis of nitrogen heterocycles, thus
Schiff Bases from TRIS and ortho-Hydroxyarenecarbaldehydes: Structures and Tautomeric Equilibria in the Solid State and in Solution
作者:R. Fernando Martínez、Martín Ávalos、Reyes Babiano、Pedro Cintas、José L. Jiménez、Mark E. Light、Juan C. Palacios
DOI:10.1002/ejoc.201100275
日期:2011.6
ascertain the influence of crystal packing on tautomeric stability, the lattice has also been simulated by computation. This protocol involves the assessment of a supramolecular cluster around a core tautomer possessing either imine or enamine structures. Such an analysis, in full agreement with solid-state data, reveals the greater stability of zwitterionic structures for the salicyl derivatives. In contrast
Imine or Enamine? Insights and Predictive Guidelines from the Electronic Effect of Substituents in H-Bonded Salicylimines
作者:R. Fernando Martínez、Esther Matamoros、Pedro Cintas、Juan C. Palacios
DOI:10.1021/acs.joc.0c00130
日期:2020.5.1
Imine and enamine bonds decorate the skeleton of numerous reagents, catalysts, and organic materials. However, it is difficult to isolate at will a single tautomer, as dynamic equilibria occur easily, even in the solid state, and are sensitive to electronic and steric effect, including π-conjugation and H-bonding. Here, using as model Schiff bases generated from salicylaldehydes and TRIS in a set of