Visible-light-mediated multi-component carbene transfer reactions of α-diazoesters to construct multisubstituted pyrazoles and 1,3-dicarbonyl derivatives

A visible-light-mediated strategy is reported for the efficient synthesis of multisubstituted pyrazoles through a three-component carbene transfer reaction of alpha-diazoesters with cyclic ethers and pyrazolones. The present transformation could be accomplished under mild and additive-free conditions to afford a wide range of multisubstituted pyrazoles with moderate to good yields and excellent functional group compatibility. It is noteworthy that a series of substituted 1,3-dicarbonyl derivatives were also conveniently obtained via visible-light-promoted three-component reaction of alpha-diazoesters, cyclic ethers, and 1,3-dicarbonyl compounds.

Automated summary

A visible-light-mediated strategy for the synthesis of multisubstituted pyrazoles through a three-component carbene transfer reaction of alpha-diazoesters with cyclic ethers and pyrazolones is reported. This transformation can be achieved under mild and additive-free conditions, yielding a wide range of multisubstituted pyrazoles with moderate to good yields and excellent functional group compatibility. Additionally, a series of substituted 1,3-dicarbonyl derivatives can be conveniently obtained via visible-light-promoted three-component reaction of alpha-diazoesters, cyclic ethers, and 1,3-dicarbonyl compounds.