From Berzelius to Hyperspace: Previously Unrecognized Network of Reactivity in Textbook Brominations.

Chemical reactions are traditionally depicted as linear equations optimized toward a single product, with other outcomes treated as minor side products. However, advances in reaction automation now allow systematic exploration of reaction "hyperspaces"-that is, multidimensional landscapes of conditions-showing that even archetypal transformations can yield previously unrecognized dominant products. Using the Robowski robotic platform with low-cost NMR detection, we scanned nearly 1000 conditions for the bromination of 1,1-diphenylethylene (DPE) and benzylideneacetone (BDA). These maps revealed new major products, condition-dependent switchovers between addition and substitution pathways, and novel substitution patterns with potential for derivatization into biologically active scaffolds. In turn, correlations and anticorrelations in product distributions across the hyperspace facilitated reconstruction of mechanistic networks connecting different outcomes. Together, our findings show that even foundational reactions, long considered mechanistically complete, harbor hidden complexity and behave as dynamic, switchable networks embedded in conditions' space.