A Mild and Efficient Synthesis of 2,5-Disubstituted 2,3-Dihydro-4-pyridones Catalyzed by Yb(OTf)₃

Abstract

A highly efficient aza-Diels-Alder reaction of trans-1-methoxy-2-methyl-3-trimethylsiloxybuta-1,3-diene with N-benz­hydryl imines was catalyzed by Yb(OTf)₃ in toluene at room temperature to give corresponding 2,5-disubstituted 2,3-dihydro-4-pyridones in high yields. Three-component reactions of diene with aldehydes and amines were also performed smoothly to afford the desired cycloadducts under solvent-free condition in 51-86% yields.

Key words

Diels-Alder reaction - N-benzhydryl imines - solvent-free - Lewis acid - three-component reaction

References

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16

The three-component reaction of benzaldehyde, benzhydrylamine and diene afforded 67% yield in toluene compared to 77% yield without solvent.