Recent Advances in Organocatalytic Asymmetric Synthesis of Bicyclo[3.3.1]nonane Frameworks

The bicyclo[3.3.1]nonane ring represents an attractive yet challenging synthetic targets in the field of organic synthesis, especially in a stereocontrolled fashion. Over the past two decades, organocatalysis has emerged as an enabling technology for the facile construction of enantioenriched molecules with remarkably increasing complexity and diversity, and a myriad of chiral architectures containing bicyclo[3.3.1]nonane units were elegantly assembled through organocatalytic asymmetric transformations. This review summarizes recent advancements on this topic (mainly from 2010 to 2023), emphasizing the reaction types such as desymmetrization and cascade reactions of different prochiral starting materials toward various chiral bicyclo[3.3.1]nonanes as well as their aza, oxa and thio derivatives. Meanwhile, the synthetic strategy, reaction mechanism, substrate scope and synthetic applications of these catalytic reactions are also discussed. We hope that this review will motivate further development and application of organocatalytic asymmetric synthesis of bicyclo[3.3.1]nonane frameworks.