Ynone

An ynone structure

In organic chemistry, an ynone is an α,β-unsaturated ketone with the structure R1C≡C‒C(=O)R2 (R2 ≠ H) in which the carbonyl (C=O) function is conjugated to a C≡C triple bond at the α,β position.[1] Capillin is an example of a naturally occurring ynone.

Subgroups

  • Diynone: an ynone with two triple bonds on both sides of the carbonyl group.
  • Bis-ynone: a structure with two ynone groups in it. These can undergo an intramolecular cycloaddition to form furan derivatives.[2]

Synthesis

One method for synthesizing ynones is the acyl substitution reaction of an alkynyldimethylaluminum with an acyl chloride. An alkynyldimethylaluminum compound is the reaction product of trimethylaluminum and a terminal alkyne.[3]

Synthesis of an ynone

An alternative is the direct coupling of an acyl chloride with a terminal alkyne, using a copper-based nanocatalyst:[4]

Synthesis of an ynone

Other methods utilize an oxidative cleavage of an aldehyde, followed by reaction with a hypervalent alkynyl iodide, using a gold catalyst.[5]

An alternative but longer synthetic method involves the reaction of an alkynyllithium compound with an aldehyde. The reaction produces a secondary alcohol that then can be oxidized via the Swern oxidation.

See also

References

  1. ↑ "CHEBI:51723 - ynone". ChEBI. ebi.ac.uk. Retrieved 18 May 2017.
  2. ↑ Wills, M.S.B.; Danheiser, R.L. (August 28, 1998). "Intramolecular [4 + 2] Cycloaddition Reactions of Conjugated Ynones. Formation of Polycyclic Furans via the Generation and Rearrangement of Strained Heterocyclic Allenes". J. Am. Chem. Soc. 120 (36): 9378–9379. doi:10.1021/ja9819209.
  3. ↑ Wang, Baomin; Bonin, Martine; Micouin, Laurent (June 22, 2005). "A Straightforward Synthesis of Ynones by Reaction of Dimethylalkynylaluminum Reagents with Acid Chlorides". J. Org. Chem. 70 (15): 6126–6128. doi:10.1021/jo050760y. Retrieved 18 May 2017.
  4. ↑ Weijiang, Sun; Wang, Yan; Wua, Xuan; Yao, Xiaoquan (2013). "Palladium-, ligand-, and solvent-free synthesis of ynones by the coupling of acyl chlorides and terminal alkynes in the presence of a reusable copper nanoparticle catalyst". Green Chemistry. 15 (9): 2356–2360. Retrieved 18 May 2017.
  5. ↑ Wang, Zhaofeng; Li, Li; Yong, Huang (August 18, 2014). "A General Synthesis of Ynones from Aldehydes via Oxidative C–C bond Cleavage under Aerobic Conditions". J. Am. Chem. Soc. 136 (35): 12233–12236. doi:10.1021/ja506352b. Retrieved 18 May 2017.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.