Oxaphospholene and oxaphosphinene heterocycles via RCM using unsymmetrical phosphonates or functional phosphinates

New phosphorus heterocycles were synthesized using RCM reaction. They were prepared from unsymmetrical or polyfunctional insaturated precursor in 50 to 87% yields solving the problem of possible competitive side reactions. In parallel hydroxyphosphinate scaffolds represent a versatile starting material and could be of great interest for the synthesis of phosphosugar libraries.