Chemical synthesis inspires chemists from many different backgrounds, and these scientists are unified in their desire to create and develop methods which enable the creation of complex target molecules from readily available starting materials. The numerous paradigm-shifts which have taken place throughout the history of synthesis have been driven largely by a single impulse: the fascination of building sophistication from simplicity – in other words, creating complexity. This Thematic Series brings together a select group of contributors, recognised for their contributions in the areas of catalysis, radical chemistry, stereoselective synthesis and molecular diversity.