Cs 2 CO 3 /CuBr 2 -promoted two-step synthesis of phenolic P-Betti bases from ( E )-2-methylene-3-cyclohexenones and diarylphosphine oxides

A novel two-step synthetic method has been established for the construction of phenolic P-Betti base derivatives. The synthetic procedure starts with a Cs2CO3-mediated P-Michael addition between diarylphosphine oxides and (E)-2-methylene-3-cyclohexenones, followed by CuBr2-promoted dehydrogenative aromatization of the generated P-Michael adducts. Under the established reaction conditions, a series of bifunctional phosphorus phenolic products were rapidly prepared in 28–81% overall yields.