Ruthenium-Catalyzed Cycloisomerization−6π-Cyclization: A Novel Route to Pyridines

Abstract
Herein we report a method for the synthesis of substituted pyridines. The unsaturated ketones and aldehydes derived from the cycloisomerization of primary and secondary propargyl diynols in the presence of [CpRu(CH3CN)3]PF6 (1) are converted to 1-azatrienes which in turn undergo a subsequent electrocyclization−dehydration to provide pyridines with excellent regiocontrol.