Bowls, Hoops, and Saddles: Synthetic Approaches to Curved Aromatic Molecules

This review summarizes recent advances in the chemistry of curved aromatic molecules. By focusing on the key accomplishments of the last decade, we provide a general overview of synthetic methods capable of efficient induction of internal strain in pi-conjugated frameworks. The review is structured according to the topology change involved in the strain-inducing reaction step (cyclizations, eliminations, ring expansions and contractions), and highlights the striking diversity of structures achievable with modern synthetic methodology.