D. N. Tomilin, L. N. Sobenina, A. B. Trofimov, A. M. Belogolova, I. A. Ushakov, N. S. Shaglaeva, B. A. Trofimov, “A facile synthesis of 2-ethynylpyrroles by Bu<sup>t</sup>OK-assisted room temperature deprotection of 2-(acylethynyl)pyrroles”, Mendeleev Commun., 2023, Volume 33, Issue 4,Pages <nobr>458

This article is cited in 1 paper

Communications

A facile synthesis of 2-ethynylpyrroles by Bu^tOK-assisted room temperature deprotection of 2-(acylethynyl)pyrroles

D. N. Tomilin^a, L. N. Sobenina^a, A. B. Trofimov^ab, A. M. Belogolova^ac, I. A. Ushakov^a, N. S. Shaglaeva^d, B. A. Trofimov^a

^a A.E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russian Federation
^b Laboratory of Quantum Chemical Modeling of Molecular Systems, Irkutsk State University, Irkutsk, Russian Federation
^c Faculty of Physics, Irkutsk State University, Irkutsk, Russian Federation
^d Institute of High Technologies, Irkutsk National Research Technical University, Irkutsk, Russian Federation

Abstract: Available N-substituted 2-(acylethynyl)pyrroles undergo room temperature deprotection in the Bu^tOK/THF system to give 2-ethynylpyrroles in 82–92% yields. Quantum-chemical calculations (B2PLYP/6-311G**//B3LYP/6-311G**+C-PCM/THF) show that the cleavage of ethynyl–acyl bond via the proton transfer from Bu^tOK with formation of potassium acylate and 2-methylpropene is thermo-dynamically much more preferred compared to alternative nucleophilic attack of tert-butoxide anion at the acyl carbon (ΔG = –35.1 vs. –2.7 kcal mol^-1).

Keywords: (acylethynyl)pyrroles, ethynylpyrroles, terminal alkynes, deacylation, deprotection, ynones, pyrroles, potassium tert-butoxide.

Language: English

DOI: 10.1016/j.mencom.2023.06.005

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