We present new chemical models of supernova (SN) ejecta based on a chemical kinetic approach. We focus on the formation of inorganic and organic molecules including gas phase dust precursors, and consider zero-metallicity progenitor, massive supernovae and nearby core-collapse supernovae such as SN1987A. We find that both types are forming large amounts of molecules in their ejecta at times as early as 200 days after explosion. Upper limits on the dust formation budget are derived. Our results on dust precursors do not agree with existing studies on dust condensation in SN ejecta. We conclude that PMSNe could be the first non-primodial molecule providers in the early universe, ejecting up to 34% of their progenitor mass under molecular form to the pristine, local gas.