This is an interesting list because it gestures toward the fact that basically any first synthesis of a compound not found in nature appears to meet the poster'

This is an interesting list because it gestures toward the fact that basically any first synthesis of a compound not found in nature appears to meet the poster's criterion. It's vanishingly uncommon for a first synthesis to have been undertaken by a true team, although this can get murky recently with drug discovery software narrowing search space. Nevertheless there is always a moment when (barring alien civilization) the compound never existed, then it does: it is nearly always one person doing the chemistry, with (at most) assistants who are fully supervised extensions of his or her will. Aspirin, for only one example, is the creation of Charles Frédéric Gerhardt.