In our optimised substrate scope conditions where we utilise 5 mol% Cs2CO3, the carbonate acts as the Brønsted base in the initial stages of the reaction in a highly thermodynamically favoured deprotonation (-45.8 kcal mol -1 , Fig. .2.1). This helps to accelerate the reaction into this propagative chain reaction and relying less on the slow initial EDA fragmentation (Fig. ).