{HEAD ~ A process} 2 or 3, wherein {TAIL ~ the phosphine oxide compound} in step c) is a triarylphosphine oxide 
{ HEAD ~ A process } 2 or 3 , wherein { TAIL ~ the phosphine oxide compound } in step c ) is a triarylphosphine oxide
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH