Energetically unfavourable Diels-Alder reaction driven by chemical fuel

Chemists have reported a rare instance of a spontaneous, energetically unfavorable reaction powered by a chemical fuel. The team took inspiration from synthetic biology, using a ratchet mechanism to drive the transformation.

For a chemical reaction to be spontaneous, it needs to release energy. This is why spontaneity, in this context, is typically reserved for exergonic reactions – those that release energy on their own. The idea behind a ratchet mechanism is to couple an energy-demanding process with an orthogonal energy input, which provides the energy necessary to satisfy the conservation of energy.