α-Hydroxy-Tetrazoles as Latent Ethynyl Moieties: A Mechanistic Investigation

Pierre Quinodoz (1) , Karen Wright (1) , Bruno Drouillat (1) , Mikhail Kletskii (2) , Oleg Burov (2) , Anton. Lisovin (2) , François Couty (1)

1 ILV - Institut Lavoisier de Versailles
2 SFEDU - Southern Federal University [Rostov-on-Don]

We report here on the dehydration of α‐hydroxy‐tetrazoles (AHTs) to yield ethynes via a vinyl carbene. The mechanism has been scrutinized by examination of the substrate and/or dehydrating agent scope and by PCM/PBE0/6‐31++G(d,p) quantum chemical calculations in CH2Cl2. This underrated transformation appears to be a viable alternative to existing methods for transforming aldehydes into alkynes. Abstract : This article focuses on the dehydration of α‐hydroxy‐tetrazoles, leading to tetraazafulvenes and then to vinylic carbenes that rearrange into ethynyl moieties through the Fritsch–Buttenberg–Wiechell rearrangement. Each step of this sequence was scrutinized, either by examination of the substrate and/or dehydrating agent scope, or through AM1 calculations, in order to understand the limiting step of this process. This underrated transformation appears to be a viable alternative to existing methods used for transforming aldehydes into alkynes.

Mots clés: Alkynes; Nitrogen heterocycles; Carbenes; Reaction mechanisms

Domaines: Chimie organique

Pierre Quinodoz, Karen Wright, Bruno Drouillat, Mikhail Kletskii, Oleg Burov, et al.. α-Hydroxy-Tetrazoles as Latent Ethynyl Moieties: A Mechanistic Investigation. European Journal of Organic Chemistry, 2019, Organic Reaction Mechanisms, 2019 (2-3), pp.342-350. ⟨10.1002/ejoc.201800143⟩. ⟨hal-02348773⟩