In a technical sense, where we are looking for a net effect greater than the sum of the two parts, Scout does synergize with lots of stuff. Top deck ordering -> Draw is going to give you more than just draw and more than just Scout (e.g. think about playing draw -> Scout for the the non-synergy version).
However, the amount of synergy is pretty close to zero and while I would take Scout for "free" with a lot of cards, Scout has a very hard time clearing any sort of opportunity cost.
Early game, Silver gets you $5 and Scout, maybe increases your cycling (it can take green out of next hand so you have higher odds hitting $5 next turn, but rarely can it do so without making you lose a $5 this turn). Later on, Scout is pretty much only useful in engines ... but then it has to repeatedly compete with engine component buys.
Practically, you can see synergy with stuff that cares a lot about top decking & maybe + action (e.g. Golem, Journeyman, Wishing well) and dual-victory cards (Nobles, Harem, Great hall). Synergy that is worth buying Scout over other stuff (like villages), pretty much just a few cases come to mind: Mystic and Herald. Both care a lot about knowledge of the top deck and both become very powerful with a small number of Scouts. I am fairly sold on Mystic and Scout is actually a pretty good "spare" buy once the Heralds are gone, but most any other synergy is less power than any other cantrip or perhaps even most non-terminals.