Tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides for the synthesis of 4-phosphorylated 4H-chromenes

A Hg(OTf)(2)-catalyzed tandem phospha-Michael addition/cyclization/dehydration of 2-hydroxychalcones with H-phosphine oxides is presented. This protocol provides a new and supplementary approach for the preparation of 4-phosphorylated 4H-chromenes in good yields (up to 99%). In addition, this domino reaction allows the successful construction of two new C-P and C-O bonds in a one-pot operation.

Automated summary

A Hg(OTf)(2)-catalyzed tandem reaction has been developed for the preparation of 4-phosphorylated 4H-chromenes. This protocol allows the construction of C-P and C-O bonds in a one-pot operation, providing a new and efficient approach for the synthesis of 4H-chromenes.