Recent Advances in Asymmetric Synthesis of Chiral Cyclobutenes

Cyclobutene scaffolds occur in natural products and bioactive compounds. Their unique structural features and intrinsic ring strain make cyclobutene a type of important building block in synthetic chemistry. In recent years, considerable efforts have been dedicated to the synthesis of chiral cyclobutenes. Enantioselective [2+2] cycloadditions and functionalization of cyclobutene derivatives have emerged as powerful and reliable protocols for achieving this goal, resulting in significant progress in this field. This review provides a comprehensive summary of the recent advancements in the asymmetric synthesis of chiral cyclobutenes, and the discussion is logically divided into four parts according to the reaction mode. Chiral cyclobutenes have been recognized as the structurally distinctive targets not only to their existence in natural products and biologically active compounds but also with their versatile reactivity in organic synthesis. Significant progress has been achieved in this domain more recently. This review aims to provide a comprehensive overview of the recent advances in the asymmetric synthesis of chiral cyclobutenes.image