An efficient synthesis of achiral and chiral 1,2,4-triazolium salts: bench stable precursors for N-heterocyclic carbenes.
[reaction: see text] The promising utility of triazolyl N-heterocyclic carbene catalysts in umpolung aldehyde chemistry requires a straightforward reliable synthesis from readily available materials. Herein, we describe the synthesis of a variety of triazolyl N-heterocyclic carbene precursors. The reactions commence from commercially available amino acids and proceed in 44-68% overall yields. The N-heterocyclic salts are air-stable crystalline solids that can be stored with no special precaution and can generate the active catalyst when treated with an appropriate base.
Kerr
Mark S
MS
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
Read de Alaniz
Javier
J
Rovis
Tomislav
T
D002384:Catalysis; D006571:Heterocyclic Compounds / Q000138:chemical synthesis; D006838:Hydrocarbons; D008697:Methane / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008956:Models, Chemical; D012492:Salts / Q000737:chemistry*; D013237:Stereoisomerism; D014230:Triazoles / Q000138:chemical synthesis*
D006571:Heterocyclic Compounds; D006838:Hydrocarbons; D012492:Salts; D014230:Triazoles; C030011:carbene; C045575:1,2,4-triazole; D008697:Methane