Annulation of Conjugated Azine-Imine with a Sulfoxonium Ylide in a Noncarbenoid Route to Synthesize Multisubstituted Imidazole-Fused Heterocycles
Sankar K. Guchhait, Meenu Saini, Viren J. Khivsara, Santosh Kumar Giri
Abstract
A new [4+1]-annulation of in situ generated heterocyclic azine-aldimines with β-keto sulfoxonium ylides has been developed. The reaction constructs N-fused imidazole rings. In the reaction, the ylides play a dual-functional role of a nucleophilic 1,1-dipolar one-carbon synthon and a source of an internal oxidant, dimethyl sulfoxide, that promotes in situ dehydrogenation to product scaffolds. The method enables access to imidazo-pyridine, pyrazine, and pyrimidine heteroaromatics.
Topics & Concepts
AnnulationChemistryAzineSynthonPyridazinePyrazineIminePyridineYlideImidazoleNucleophileCombinatorial chemistryDehydrogenationOrganic chemistryNucleophilic additionMedicinal chemistryCatalysisCyclopropane Reaction MechanismsCatalytic C–H Functionalization MethodsSynthesis and Catalytic Reactions