Photochemical and Additive-Free Coupling Reaction of α-Cumyl α-Keto Esters via Intermolecular C–H Bond Activation

Abstract

We developed a photo-chemical coupling reaction of α-keto esters with several simple alcohols, alkanes, ethers, and amides. Use of tertiary alkyl ester, α-cumyl ester, is the key for avoiding the known photo-degradation process. Intermolecular C–H bond activation and subsequent C–C bond formation were promoted by irradiation with an LED lamp (365 nm) without any additives. Among the coupling partners, reactions with sterically less demanding amides proceeded efficiently to provide unique N-acyl-β-amino-α-hydroxy acid derivatives. In benzene or acetone as a solvent, the reaction with a solid amino acid derivative provided a precursor of tetrahydro-1,4-diazepine-2,5-dione derivatives.

Key words

photo-chemical reaction - α-keto esters - coupling reactions - C–H bond activation - β-amino acid derivatives - α-cumyl esters - tetrahydro-1,4-diazepine-2.5-dione

• References and Notes

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No tetrahydro-1,4-diazepine-2.5-dione derivative with this substitution pattern has been reported. For similar examples, see:
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