New linked macrocyclic systems derived from selectively protected S2N2 macrocycles

Novel application of a protecting group strategy has enabled a simple and efficient synthesis of the new tri-linked S2N2 macrocycles 12, 15, 17 and 20. This strategy involves the introduction of complementary protecting groups (R1 and R2) into the precursor macrocycle 4, which can then be manipulated to provide a synthetically versatile set of mono-N-protected S2N2 macrocylic building blocks 5, 7 and 8.