<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A highly reductive photoredox system based on heterogeneous platinum nanoparticles on titania as catalyst is described to allow hydrodehalogenation of iodoarenes, hydrodehalogenation and cyclization of a variety of allyl and propargyl tethered iodoethyl compounds, and the cyclization of bisenones of type (XVII).</p> </abstract>