Grambow et al. only searched for elementary reactions starting from single reactant molecules, but they found a lot of products with two fragments. From these back-reactions, we extract a set of 20 target low-barrier reactions where two molecules react to create a single molecule (Table ). While these reactions are not necessarily the ones with the lowest barrier for a given pair of reactant molecules, our method should be able to identify them along with any reactions with lower barriers. The meta-MD simulations identify 19 of the 20 products found by Grambow et al., while the subsequent semiempirical screening eliminates an additional reaction due to at an overestimation of the barrier height relative to DFT. In addition, we find 34 new low-barrier reactions. We found that it is necessary to "encourage" the reactants to go to previously undiscovered products, by including products found by other MD simulations when computing the biasing potential as well as decreasing the size of the molecular cavity in which the MD occurs, until a reaction is observed.