Abstract
<jats:p>Automated exploration of organometallic reaction mechanisms remains limited by the absence of molecular representations and enumeration rules that capture dative bonding, and by the computational cost of transition state refinement with large basis sets. Here, methodological extensions to the Yet Another Reaction Program (YARP) are introduced that encode dative metal-ligand contacts within the bond-electron formalism and automate a mixed-basis workflow for high-throughput organometallic reaction exploration. Together, these additions place transition state optimization for organometallic reactions on an even footing with analogous organic reaction exploration. Benchmarks across oxidative addition, reductive elimination, migratory insertion, β-hydride elimination, C-H activation, and transmetalation reproduce literature energetics within a few kilocalories per mole at a fraction of the cost of uniform triple-zeta treatments, and systematic conformational searches identify lower-energy transition state geometries in several cases than the literature references. The framework also enables targeted enumeration of plausible side reactions. These results demonstrate a practical path toward general-purpose, cost-aware reaction exploration for transition-metal systems.</jats:p>