Chapter 5
Conclusions
In the six decades following the initial synthetic report on the use of NIs, an enormous
number of publications have exploited the unique properties of this valuable species.
The 2007 rediscovery of the benefits of 2,5-diaryl tetrazole photolysis in particular
has revitalised the field [1], with a number of new and exciting applications of the
dipole emerging, relative to the limited literature activity of the 1980s and 1990s.
Of additional significance is the recent reevaluation of carboxylic acids and thiols
as potent NI reaction partners [2]. While initially stimulating the development of
additional applications of NIs exploiting this reactivity [3, 4], it has also prompted
a reassessment of the orthogonality of “tetrazole photoclick chemistry”, which has
in turn led to the development of much improved NI and alkenyl functional handles
within this field [5, 6]. Future research will likely focus on the additional applications
of photolytically generated NIs with alkenes and carboxylic acids, although as evidenced from some of the conflicting reports in Sect. 3, a greater understanding of the
complete reactivity profile of NIs is essential, and is still somewhat under-explored.
Nevertheless, the NI remains a species of significant potential in numerous fields of
chemistry, and will likely be the subject of a substantial body of research well into
the future.
References
1. Wang Y, Rivera CI, Vera A, Lin Q (2007) Convenient synthesis of highly functionalized
Pyrazolines via mild, photoactivated 1,3-dipolar cycloaddition. Org Lett 9:4155–4158
2. Li Z, Qian L, Li L, Bernhammer JC, Huynh HV, Lee J-S, Yao SQ (2015) Tetrazole photoclick
chemistry: reinvestigating its suitability as a bioorthogonal reaction and potential applications.
Angew Chem Int Ed Engl 55:2002–2006
3. Herner A, Marjanovic J, Lewandowski TM, Marin V, Patterson M, Miesbauer L, Ready D,
Williams J, Vasudevan A, Lin Q (2016) 2-Aryl-5-carboxytetrazole as a new photoaffinity label
for drug target identification. J Am Chem Soc 138:14609–14615
4. Heiler C, Offenloch JT, Blasco E, Barner-Kowollik C (2017) Photochemically induced folding
of single chain polymer nanoparticles in water. ACS Macro Lett 6:56–61
© Springer Nature Switzerland AG 2020
C. Jamieson and K. Livingstone, The Nitrile Imine 1,3-Dipole,
https://doi.org/10.1007/978-3-030-43481-6_5
151
Conclusions
In the six decades following the initial synthetic report on the use of NIs, an enormous
number of publications have exploited the unique properties of this valuable species.
The 2007 rediscovery of the benefits of 2,5-diaryl tetrazole photolysis in particular
has revitalised the field [1], with a number of new and exciting applications of the
dipole emerging, relative to the limited literature activity of the 1980s and 1990s.
Of additional significance is the recent reevaluation of carboxylic acids and thiols
as potent NI reaction partners [2]. While initially stimulating the development of
additional applications of NIs exploiting this reactivity [3, 4], it has also prompted
a reassessment of the orthogonality of “tetrazole photoclick chemistry”, which has
in turn led to the development of much improved NI and alkenyl functional handles
within this field [5, 6]. Future research will likely focus on the additional applications
of photolytically generated NIs with alkenes and carboxylic acids, although as evidenced from some of the conflicting reports in Sect. 3, a greater understanding of the
complete reactivity profile of NIs is essential, and is still somewhat under-explored.
Nevertheless, the NI remains a species of significant potential in numerous fields of
chemistry, and will likely be the subject of a substantial body of research well into
the future.
References
1. Wang Y, Rivera CI, Vera A, Lin Q (2007) Convenient synthesis of highly functionalized
Pyrazolines via mild, photoactivated 1,3-dipolar cycloaddition. Org Lett 9:4155–4158
2. Li Z, Qian L, Li L, Bernhammer JC, Huynh HV, Lee J-S, Yao SQ (2015) Tetrazole photoclick
chemistry: reinvestigating its suitability as a bioorthogonal reaction and potential applications.
Angew Chem Int Ed Engl 55:2002–2006
3. Herner A, Marjanovic J, Lewandowski TM, Marin V, Patterson M, Miesbauer L, Ready D,
Williams J, Vasudevan A, Lin Q (2016) 2-Aryl-5-carboxytetrazole as a new photoaffinity label
for drug target identification. J Am Chem Soc 138:14609–14615
4. Heiler C, Offenloch JT, Blasco E, Barner-Kowollik C (2017) Photochemically induced folding
of single chain polymer nanoparticles in water. ACS Macro Lett 6:56–61
© Springer Nature Switzerland AG 2020
C. Jamieson and K. Livingstone, The Nitrile Imine 1,3-Dipole,
https://doi.org/10.1007/978-3-030-43481-6_5
151