Sterically Shielded Stable Carbenes and Biscarbenes of the 1,2,4‐Triazole Series: A New Method for the Preparation of 1,3,4‐Triaryl‐1,2,4‐triazol‐5‐ylidenes

• DOI: 10.1002/slct.201800658
• Publication Date: 2018-05-24T08:27:48Z
• Authors: Nataliya V. Gliny...; Nikolai I. Korotkikh; Alan H. Cowley; Owen Williams; Richard A. Jones; Vincent M. Lynch; Artyom V. Kiselyov; Gennady F. Rayenko; Maria A. Derevenets; Alexey B. Ryabitsky; Orhi Esarte Palomero; Oles P. Shvaika
• Keywords: Triazole

Abstract The 1‐adamantyl substituted stable carbene 5 and the biscarbene 9 of 1,2,4‐triazole series with sterically shielding groups at position 4 heterocyclic ring (dbmp, dipp) have been synthesized in three steps starting from derivatives 1,3,4‐oxadiazole 1,6 . A new method for preparation 1,3,4‐triaryl‐1,2,4‐triazol‐5‐ylidenes ( 14 a‐c ) has also proposed includes Vilsmeier reaction 2‐benzoyl‐1‐formylphenylhydrazine phosphorus chloroxide aromatic amines, followed by deprotonation obtained 1,3,4‐triaryl‐1,2,4‐triazolium salts. allows introduction steric substituents to 4‐position heterocycle. resulting carbenes show promise as nucleophilic catalysts ligands complex organic reactions.