Introducing topology to assess the synchronicity of organic reactions. Dual reactivity of oximes with alkenes as a case study

The synchronicity of organic reactions not always can be determined by only the analysis of transition structures. We present a case study that illustrates that topological analyses provide information regarding synchronicity that, often, is not reflected in the geometry of transition structures. We have chosen the competitive reactions of oximes with alkenes, (3 + 2) dipolar cycloaddition and ene-like reaction, which have been computationally studied to determine the parameters favoring each process. The competition between the two reactions is particularly evidenced in alkenyl oximes leading to intramolecular processes. Up to 26 examples of intramolecular reactions have been calculated and the results predicted the favored process.This work was supported by the Spanish Ministerio de Economía y Competitividad (MINECO) (project number CTQ2016-76155-R), the Fondos Europeos para el Desarrollo Regional (FEDER) and the Gobierno de Aragón (Zaragoza, Spain, Bioorganic Chemistry Group, E-10). The authors acknowledge the Institute of Biocomputation and Physics of Complex Systems (BIFI) at the University of Zaragoza for computer time at the clusters Terminus and Memento. M.-A. C. and L. L. thank the University of Catania and University of Pavia for partial financial support.Peer reviewe