All 28 of the substrates were represented in these reactions, both as a limiting substrate and as a substrate used in excess. The reactions were performed in microscale vials in 96-well plate format on a 100 l scale (with 10 mol limiting substrate). The reactions were assembled from stock solutions in acetonitrile using pipettes. Each reaction involved a limiting substrate (final concentration 100 mM), a second (different) substrate (final concentration 300 mM) and Ir[dF(CF3)ppy]2(dtbpy)PF6 (final concentration 2 mM); some reactions also involved TRIP-thiol (final concentration: 50 mM) or TBPA (final concentration: 200 mM), and/or TFA (final concentration: 200 mM). The array of vials was irradiated with two 40 W Kessil A160WE Tuna Blue lamps for 16 h. The outcome of the reactions was determined by analytical HPLC/MS with, additionally, evaporative lightscattering detection to enable determination of the approximate yield of each product.