Brønsted Acid-Thiourea Co-catalysis: Asymmetric Synthesis of Function­alized 1,4-Dihydropyridines from β-Enamino Esters and α,β-Unsaturated ­Aldehydes

Abstract

LETTER 1865Brønsted Acid-Thiourea Co-catalysis: Asymmetric Synthesis of Functionalized 1,4-Dihydropyridines from b-Enamino Esters and a,b-Unsaturated Aldehydes A s y m m e t r i c S y n t h e s i s o f F u n c t i o n a l i z e d 1 , 4 -D i h y d r o p y r i d i n e sAbstract: A Brønsted acid and a novel thiourea derivative co-catalyze the addition of b-enamino esters to a,b-unsaturated aldehydes leading to functionalized 1,4-dihydropyridines with moderate to good enantioselectivity. A regioselective synthesis of 1,2-dihydropyridines from a,b-unsaturated aldehydes is also described.

Diethyl 4-(2-methoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

“…For general background to 1,4-dihydropyridine compounds, see: Franke et al (2008); Takemoto et al (2010). For related structures, see: Fun et al (2012); Kapoor et al (2011).…”