Diisopropyl azodicarboxylate (DIAD) is the diisopropyl ester of azodicarboxylic acid. It is used as a reagent in the production of many organic compounds. It is often used with triphenylphosphine in the Mitsunobu reaction,[2] wherein it serves as a hydride acceptor. It has also been used to generate aza-Baylis-Hillman adducts with acrylates.[3] It can also serve as a selective deprotectant of N–benzyl groups in the presence of other protecting groups.[4]
It is sometimes preferred to diethyl azodicarboxylate (DEAD) because it is more hindered, and thus less likely to form hydrazide byproducts.
Under conditions relevant to the Mitsunobu reaction (in the presence of triphenylphosphine at high concentrations), DIAD has been shown by EPR spectroscopy to form a highly unusual tetrazetidine radical cation (a square of nitrogen atoms), corresponding to formal [2+2]-cycloaddition of the N=N bonds of two molecules of DIAD along with loss of a single electron.[5]
One notable use of this compound is in the synthesis of bifenazate.[citation needed]
References
- ^ https://pubchem.ncbi.nlm.nih.gov/compound/5363146#section=IUPAC-Name&fullscreen=true
- ^ “luka DIAD on Sigma-Aldrich”. Archived from the original on 2008-04-24. Retrieved 2008-11-18.
- ^ Shi, Min; Zhao, Gui-Ling (2004). “Aza-Baylis–Hillman reactions of diisopropyl azodicarboxylate or diethyl azodicarboxylate with acrylates and acrylonitrile”. Tetrahedron. 60 (9): 2083–2089. doi:10.1016/j.tet.2003.12.059.
- ^ Kroutil, J.; Trnka, T.; Cerny, M. (2004). “Improved procedure for the selective N-debenzylation of benzylamines by diisopropyl azodicarboxylate”. Synthesis. 3 (3): 446–450. doi:10.1055/s-2004-815937.
- ^ Camp, David; Campitelli, Marc; Hanson, Graeme R.; Jenkins, Ian D. (2012-10-03). “Formation of an Unusual Four-Membered Nitrogen Ring (Tetrazetidine) Radical Cation”. Journal of the American Chemical Society. 134 (39): 16188–16196. doi:10.1021/ja303019y. ISSN 0002-7863.