Garratt–Braverman Cyclization, a Powerful Tool for C–C Bond Formation

Abstract

Development of new strategies for C–C bond formation remains in the forefront of organic synthesis. The base-mediated rearrangement of bis-propargyl sulfones via bis-allenes generated in situ, now known as the Garratt–Braverman cyclization (GBC), leads to the formation of two new C–C bonds. The reaction has recently drawn attention from organic chemists due to the wide scope as well as interesting mechanism. This report aims to give an account of the developments in this area with particular emphasis on synthetic applications. 1 Introduction 2 Biradical-Generating Reactions 3 Fate of Biradicals 4 Garratt–Braverman Cyclization; A Historical Development 5 Exploration of Garratt–Braverman Chemistry in Organic Synthesis 5.1 Braverman’s Work 5.2 Feldman’s Work 5.3 Contribution from the Author’s Group 6 Competition between GBC and Biradical/Concerted Cyclization Reactions 6.1 GBC vs. MSC/SC 6.2 GBC vs. 6π-Electrocyclization 6.3 GBC vs. Nucleophilic Addition 7 Conclusion and Future Aspects