Synthesis of 4-Alkylated 1,4-Dihydropyridines: Fe(II)-Mediated Oxidative Cascade Cyclization Reaction of Cyclic Ethers with Enaminones

Syntheses of highly functionalized 4-alkylated 1,4-dihydropyridines(1,4-DHPs) from cyclic ethers and enaminones via iron(II)-mediatedoxidative free radical cascade C(sp(3))-H bond functionalization/C(sp(3))-O bond cleavage/cyclization reaction have been firstdeveloped. This novel synthetic strategy offers an alternative methodfor the construction of 1,4-DHPs by using esters as the C4 sources,as well as expands the application of ethers in heterocycle synthesis.

Automated summary

Highly functionalized 4-alkylated 1,4-dihydropyridines (1,4-DHPs) are synthesized for the first time from cyclic ethers and enaminones via iron(II)-mediated oxidative free radical cascade C(sp(3))-H bond functionalization/C(sp(3))-O bond cleavage/cyclization reaction. This novel synthetic strategy provides an alternative method for the construction of 1,4-DHPs using esters as the C4 sources, and expands the application of ethers in heterocycle synthesis.