Context-Driven Exploration of Complex Chemical Reaction Networks

The construction of a reaction network
containing all relevant
intermediates and elementary reactions is necessary for the accurate
description of chemical processes. In the case of a complex chemical
reaction (involving, for instance, many reactants or highly reactive
species), the size of such a network may grow rapidly. Here, we present
a computational protocol that constructs such reaction networks in
a fully automated fashion steered in an intuitive, graph-based fashion
through a single graphical user interface. Starting from a set of
initial reagents new intermediates are explored through intra- and
intermolecular reactions of already explored intermediates or new
reactants presented to the network. This is done by assembling reactive
complexes based on heuristic rules derived from conceptual electronic-structure
theory and exploring the corresponding approximate reaction path.
A subsequent path refinement leads to a minimum-energy path which
connects the new intermediate to the existing ones to form a connected
reaction network. Tree traversal algorithms are then employed to detect
reaction channels and catalytic cycles. We apply our protocol to the
formose reaction to study different pathways of sugar formation and
to rationalize its autocatalytic nature.