Misplaced Pages

Acyl cyanide

Article snapshot taken from[REDACTED] with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.
Chemical group (–C(O)C≡N)
General chemical structure of an acyl cyanide

In organic chemistry, an acyl cyanide is a functional group with the formula R−C(O)CN and structure R−C(=O)−C≡N. It consists of an acyl group (R−C=O) attached to cyanide (−C≡N). Examples include acetyl cyanide, formyl cyanide, and oxalyl dicyanide. Acyl cyanides are reagents in organic synthesis.

Synthesis

Classically acyl cyanides are produced by the salt metathesis reaction of acyl chlorides with sodium cyanide:

R − C ( O ) Cl + Na CN ⟶ R − C ( O ) CN + NaCl {\displaystyle {\color {red}{\ce {R-C(O)}}}{\ce {Cl}}+{\ce {Na}}{\color {red}{\ce {CN}}}\longrightarrow {\color {red}{\ce {R-C(O)CN}}}+{\ce {NaCl}}}

Alternatively, they can be produced by dehydration of acyl aldoximes:

R − C ( O ) C H = N OH ⟶ R − C ( O ) CN + H 2 O {\displaystyle {\color {red}{\ce {R-C(O)C}}}{\ce {H=}}{\color {red}{\ce {N}}}{\ce {OH}}\longrightarrow {\color {red}{\ce {R-C(O)CN}}}+{\ce {H2O}}}

Acetyl cyanide is also prepared by hydrocyanation of ketene:

CH 2 = C = O + H CN ⟶ H 3 C − C ( O ) CN {\displaystyle {\ce {CH2=}}{\color {red}{\ce {C=O}}}+{\ce {H}}{\color {red}{\ce {CN}}}\longrightarrow {\ce {H3C -}}{\color {red}{\ce {C(O)CN}}}}

Reactions

They are mild acylating agents. With aqueous base, acyl cyanides break down to cyanide and the carboxylate:

R − C ( O ) CN + 2 NaOH ⟶ R − CO Na 2 + Na CN + H 2 O {\displaystyle {\color {red}{\ce {R-C(O)CN}}}+{\ce {2 NaOH}}\longrightarrow {\color {red}{\ce {R-CO}}}{\ce {_2Na}}+{\ce {Na}}{\color {red}{\ce {CN}}}+{\ce {H2O}}}

With azides, acyl cyanides undergo the click reaction to give acyl tetrazoles.

References

  1. Liu, Bing; Wang, Yong; Chen, Ying; Wu, Qian; Zhao, Jing; Sun, Jianwei (2018). "Stereoselective Synthesis of Fully-Substituted Acrylonitriles via Formal Acylcyanation of Electron-Rich Alkynes". Organic Letters. 20 (12): 3465–3468. doi:10.1021/acs.orglett.8b01180. PMID 29873500. S2CID 46942109.
  2. ^ Morris, Joel (2001). "Acetyl Cyanide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.ra026. ISBN 0471936235.
  3. Hünig, Siegfried; Schaller, Rainer (1982). "The Chemistry of Acyl Cyanides". Angewandte Chemie International Edition in English. 21: 36–49. doi:10.1002/anie.198200361.
  4. Demko, Zachary P.; Sharpless, K. Barry (2002). "A Click Chemistry Approach to Tetrazoles by Huisgen 1,3-Dipolar Cycloaddition: Synthesis of 5-Acyltetrazoles from Azides and Acyl Cyanides". Angewandte Chemie International Edition. 41 (12): 2113–2116. doi:10.1002/1521-3773(20020617)41:12<2113::AID-ANIE2113>3.0.CO;2-Q. PMID 19746613.
Categories:
Acyl cyanide Add topic