Acyl azide

Acyl azides are carboxylic acid derivatives with the general formula RCON₃. These compounds, which are a subclass of organic azides, are generally colorless.¹

Preparation

Typically acyl azides are generated under conditions where they rearrange to the isocyanate.¹

Acid chlorides²³ and anhydrides⁴ react with sodium azide⁵ or trimethylsilyl azide⁶ to give acyl azides:

In a Mitsunobu variant, triphenylphosphine and trichloroacetonitrile catalyze excellent yields from various carboxylic acids and sodium azide at mild conditions.⁷

The second major route to azides is from treating acylhydrazines with nitrous acid.¹⁸ Alternatively, the acyl azide can be formed by the direct reaction of a carboxylic acid with diphenylphosphoryl azide (DPPA).⁹¹⁰

Methods of forming acyl azides from carboxylic acids source ↗

Another route oxidizes aldehydes with iodine azide, formed from sodium azide and iodine monochloride in acetonitrile.¹¹

Uses

On Curtius rearrangement, acyl azides yield isocyanates.¹²¹³

Acyl azides are also formed in Darapsky degradation,¹⁴¹⁵¹⁶

Acyl azides react with amines to give aminimides (R₃N⁺N⁻C(=O)R′).¹⁷

Historical references

Curtius, Th. (1890). "Ueber Stickstoffwasserstoffsäure (Azoimid) N₃H". Ber. (in German). 23 (2): 3023–3033. doi:10.1002/cber.189002302232.
Curtius, Th. (1894). "20. Hydrazide und Azide organischer Säuren I. Abhandlung". J. Prakt. Chem. (in German). 50 (1): 275–294. doi:10.1002/prac.18940500125.
Darapsky, August (1936). "Darstellung von α-Aminosäuren aus Alkyl-cyanessigsäuren". J. Prakt. Chem. (in German). 146 (8–12): 250–267. doi:10.1002/prac.19361460806.
Darapsky, August; Hillers, Dietrich (1915). "Über das Hydrazid der Cyanessigsäure, Isonitrosocyanessigsäure und Nitrocyanessigsäure". J. Prakt. Chem. (in German). 92 (1): 297–341. doi:10.1002/prac.19150920117.

References

Lwowski, Walter (1971). "Acyl azides". In Saul Patai (ed.). The Azido Group. PATAI'S Chemistry of Functional Groups. pp. 849–907. doi:10.1002/9780470771266.ch9. ISBN 9780470771679.
Allen, C. F. H.; Bell, Alan (1944). "Undecyl isocyanate". Organic Syntheses. 24: 94. doi:10.15227/orgsyn.024.0094.
Munch-Petersen, Jon (1953). "m-Nitrobenzazide (Benzoyl azide, m-nitro-)". Organic Syntheses. 33: 53. doi:10.15227/orgsyn.033.0053.
Weinstock, J (1961). "Modified Curtius reaction". J. Org. Chem. 26: 3511. doi:10.1021/jo01067a604.
Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 948. ISBN 978-0387683546.
Warren, J. D.; Press, J. B. (1980). "Formation and Curtius rearrangement of acyl azides from unreactive acid chlorides". Synth. Commun. 10: 107–110. doi:10.1080/00397918008061812.
Jang, Doo; Kim, Joong-Gon (2008). "Direct Synthesis of Acyl Azides from Carboxylic Acids by the Combination of Trichloroacetonitrile, Triphenylphosphine and Sodium Azide". Synlett. 2008 (13): 2072–2074. doi:10.1055/s-2008-1077979.
Pozsgay, V.; Jennings, H. J. (1987). "Azide synthesis with stable nitrosyl salts". Tetrahedron Lett. 28 (43): 5091–5092. doi:10.1016/s0040-4039(00)95598-9.
Shioiri, T.; Ninomiya, K.; Yamada, S. (1972). "New convenient reagent for a modified Curtius reaction and for peptide synthesis". J. Am. Chem. Soc. 94 (17): 6203–6205. doi:10.1021/ja00772a052. PMID 5054412.
Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 948. ISBN 978-0387683546.
Marinescu, Lavinia; Thinggaard, Jacob; Thomsen, Ib B.; Bols, Mikael (2003). "Radical Azidonation of Aldehydes". J. Org. Chem. 68 (24): 9453–9455. doi:10.1021/jo035163v. PMID 14629171.
Smith, Peter A. S. (1946). "The Curtius reaction". Org. React. 3: 337–449. doi:10.1002/0471264180.or003.09. ISBN 0471264180. {{cite journal}}: ISBN / Date incompatibility (help)
Scriven, Eric F. V.; Turnbull, Kenneth (1988). "Azides: Their preparation and synthetic uses". Chem. Rev. 88 (2): 297–368. doi:10.1021/cr00084a001.
Gagnon, Paul E.; Boivin, Paul A.; Craig, Hugh M. (1951). "Synthesis of Amino Acids from Substituted Cyanoacetic Esters". Can. J. Chem. 29 (1): 70–75. doi:10.1139/v51-009.
E. H. Rodd (1965). Chemistry of Carbon Compounds (2nd ed.). New York. p. 1157.{{cite book}}: CS1 maint: location missing publisher (link)
Gagnon, Paul E.; Nadeau, Guy; Côté, Raymond (1952). "Synthesis of α-Amino Acids from Ethyl Cyanoacetate". Can. J. Chem. 30 (8): 592–597. doi:10.1139/v52-071.
Wawzonek, Stanley (1980). "Chemistry of Aminimides". Industrial & Engineering Chemistry Product Research and Development. 19 (3): 338–349. doi:10.1021/i360075a013. ISSN 0196-4321.

[Patai-1] Lwowski, Walter (1971). "Acyl azides". In Saul Patai (ed.). The Azido Group. PATAI'S Chemistry of Functional Groups. pp. 849–907. doi:10.1002/9780470771266.ch9. ISBN 9780470771679.

[2] Allen, C. F. H.; Bell, Alan (1944). "Undecyl isocyanate". Organic Syntheses. 24: 94. doi:10.15227/orgsyn.024.0094.

[3] Munch-Petersen, Jon (1953). "m-Nitrobenzazide (Benzoyl azide, m-nitro-)". Organic Syntheses. 33: 53. doi:10.15227/orgsyn.033.0053.

[4] Weinstock, J (1961). "Modified Curtius reaction". J. Org. Chem. 26: 3511. doi:10.1021/jo01067a604.

[5] Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 948. ISBN 978-0387683546.

[6] Warren, J. D.; Press, J. B. (1980). "Formation and Curtius rearrangement of acyl azides from unreactive acid chlorides". Synth. Commun. 10: 107–110. doi:10.1080/00397918008061812.

[kim-7] Jang, Doo; Kim, Joong-Gon (2008). "Direct Synthesis of Acyl Azides from Carboxylic Acids by the Combination of Trichloroacetonitrile, Triphenylphosphine and Sodium Azide". Synlett. 2008 (13): 2072–2074. doi:10.1055/s-2008-1077979.

[8] Pozsgay, V.; Jennings, H. J. (1987). "Azide synthesis with stable nitrosyl salts". Tetrahedron Lett. 28 (43): 5091–5092. doi:10.1016/s0040-4039(00)95598-9.

[9] Shioiri, T.; Ninomiya, K.; Yamada, S. (1972). "New convenient reagent for a modified Curtius reaction and for peptide synthesis". J. Am. Chem. Soc. 94 (17): 6203–6205. doi:10.1021/ja00772a052. PMID 5054412.

[10] Carey, Francis A.; Sundberg, Richard J. (2007). Advanced Organic Chemistry: Part B: Reactions and Synthesis (5th ed.). New York: Springer. p. 948. ISBN 978-0387683546.

[marinescu-11] Marinescu, Lavinia; Thinggaard, Jacob; Thomsen, Ib B.; Bols, Mikael (2003). "Radical Azidonation of Aldehydes". J. Org. Chem. 68 (24): 9453–9455. doi:10.1021/jo035163v. PMID 14629171.

[12] Smith, Peter A. S. (1946). "The Curtius reaction". Org. React. 3: 337–449. doi:10.1002/0471264180.or003.09. ISBN 0471264180. {{cite journal}}: ISBN / Date incompatibility (help)

[13] Scriven, Eric F. V.; Turnbull, Kenneth (1988). "Azides: Their preparation and synthetic uses". Chem. Rev. 88 (2): 297–368. doi:10.1021/cr00084a001.

[14] Gagnon, Paul E.; Boivin, Paul A.; Craig, Hugh M. (1951). "Synthesis of Amino Acids from Substituted Cyanoacetic Esters". Can. J. Chem. 29 (1): 70–75. doi:10.1139/v51-009.

[15] E. H. Rodd (1965). Chemistry of Carbon Compounds (2nd ed.). New York. p. 1157.{{cite book}}: CS1 maint: location missing publisher (link)

[16] Gagnon, Paul E.; Nadeau, Guy; Côté, Raymond (1952). "Synthesis of α-Amino Acids from Ethyl Cyanoacetate". Can. J. Chem. 30 (8): 592–597. doi:10.1139/v52-071.

[17] Wawzonek, Stanley (1980). "Chemistry of Aminimides". Industrial & Engineering Chemistry Product Research and Development. 19 (3): 338–349. doi:10.1021/i360075a013. ISSN 0196-4321.

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