A single chemical reaction is said to be autocatalytic if one of the reaction products is also a catalyst for the same or a coupled reaction. Such a reaction is called an autocatalytic reaction.
In other words a kind of PositiveFeedbackLoop of chemical reactions.
StuartKauffman studied them, and showed the principle that they were much more common / probable than you might intuitively imagine.
In fact this kind of self-reinforcing, self-creating networks of reactions are so "normal" that they might be valid explanations for the emergence of order / structure / life.
See also :