Tracing the Chemistry of Massive Stars Before They Shine: A Tour Through High-Mass Star-Forming Regions

High-mass stars form in dense, distant, and fast-evolving environments that produce distinct chemical signatures. The chemistry progresses from simple, highly deuterated molecules in cold starless cores to rich complex organic molecules in warmer protostellar objects, then becomes dominated by ultraviolet-driven processes in H II regions. Upcoming ALMA and JWST observations are expected to clarify this chemical evolution and its implications for star and planet formation.