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
Key words
alkynes - cyclizations - ene reactions - polyclyclic compounds - radicals - sulfones