All commercially available reagents were used as received. 4 Anhydrous solvents were dried prior to use according to standard methods. GPR-grade solvents were used for flash chromatography purposes. Solution-phase synthetic reactions were carried out using oven-dried glassware. All concentrations were performed in vacuo unless otherwise stated. Thin layer chromatography was carried out on Merck silica gel 60 F254 precoated aluminium foil sheets and these were visualized using UV light (254 nm).