Abstract
Nitrilium betaine 1,3-dipoles are ubiquitous reagents in organic chemistry, with applications
ranging from natural product synthesis to materials science. Given the high reactivity
of these zwitterionic motifs, they are invariably generated in situ from a suitable
precursor, prior to use. This short review summarises the recent progress in the development
of modern approaches towards the formation of these 1,3-dipoles, and their applications
within a diverse range of fields.
1 Introduction
2 Nitrile Ylides
2.1 2H-Azirine Rearrangement
2.2 Addition of Nitriles to Carbenes
3 Nitrile Imines
3.1 2,5-Tetrazole Thermolysis
3.2 2,5-Tetrazole Photolysis
3.3 Diaryl Sydnone Photolysis
4 Nitrile Oxides
4.1 Hypervalent Iodine
4.2 The Nitroso Radical
4.3 Green Chemistry Approaches
4.4 Other Approaches
5 Conclusions
Key words
1,3-dipole - dipolar cycloaddition - nitrilium betaine - nitrile ylide - nitrile imine
- nitrile oxide - photochemistry
