One-pot (2 + 4) cycloaddition of propargyl alcohols with <i>o</i>-hydroxyphenyl substituted secondary phosphine oxides

A copper-catalyzed one-pot (2 + 4) cycloaddition of propargyl alcohols with <i>o</i>-hydroxyphenyl-substituted secondary phosphine oxides was established, affording a series of six-membered P(V)-containing heterocycles in high yields (up to 98%). More importantly, biological activity screening of these six-membered P(V)-containing heterocycles demonstrated their <i>in vitro</i> inhibitory effect on the proliferation of MCF-7 human breast cancer cells. This reaction not only represents the first cycloaddition involving propargyl alcohols with phosphorus-containing dinucleophiles but also provides access to a class of potential biologically active P(V)-containing heterocycles.