1. One-Pot Synthesis of Highly Substituted N-Fused Heteroaromatic Bicycles from Azole Aldehydes
- Author
-
Craig A. Townsend, Felipe B. d’Andrea, and Victor K. Outlaw
- Subjects
chemistry.chemical_classification ,Annulation ,Molecular Structure ,Pyridines ,Organic Chemistry ,One-pot synthesis ,Indolizines ,Substituent ,Stereoisomerism ,Alkylation ,Biochemistry ,Medicinal chemistry ,Article ,chemistry.chemical_compound ,chemistry ,Wittig reaction ,Electrophile ,Azole ,Organic chemistry ,Physical and Theoretical Chemistry - Abstract
An efficient route to substituted N-fused aromatic heterocycles, including indolizines, imidazo[1,2-a]pyridines, and imidazo[1,5-a]pyridines from azole aldehydes is reported. A three-component Wittig olefination of the aldehydes with fumaronitrile and triethylphosphine affords predominantly E-alkenes that undergo rapid cyclization upon in situ treatment with catalytic amounts of mild base. Substituent control of the 1-, 2-, and 3-positions of the resulting heteroaromatic bicycles is shown. Alternatively, the isolable E-alkene product from pyrrole-2-carboxaldehyde, under dianionic conditions, undergoes selective alkylation with various electrophiles, followed by in situ annulation to indolizines additionally substituted at the 6-position.
- Published
- 2015
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