To illustrate the synthetic validity of the approach, the synthesis of thiourea-urea 2 through the four-step cyclic sequence was performed on a larger scale (1.2 10 -2 mmol of Ox3 instead of 1.8 10 -3 mmol) in CHCl3/CH3CN (9:1). After 3 cycles, only the presence of the desired thioureaurea 2 was detected by 1 H NMR analysis of the crude mixture (> 90% NMR yield). After acidic washings to remove the DBU, thiourea-urea 2 was isolated through purification by flash chromatography (FC) in 75% isolated yield. As one could have expected with a thiourea-urea compound, purification of 2 by FC was quite complicated, explaining in part the small discrepancy between the NMR and isolated yields. Extension of the strategy to reactions between different monoprotected substrates. The next challenge was to see if the supramolecular protection approach could be applied to reactions between different monoprotected diamines. Such an extension of the strategy would enable the straightforward one-pot synthesis of products difficult to access through classical synthetic methods. For example, to avoid the formation of polymers, the classical preparation of the simple diamino-diurea 4 from symmetrical diamines would require a very demanding multistep synthesis involving non-selective protection/tricky separation/deprotection steps (Scheme 3). Only a very low global yield could be expected from such an approach.