Novel sulfur-containing amidecrownophanes: synthesis via tandem Claisen rearrangement and an unpredicted mercuration

Two novel sulfur-containing amidecrownophanes, 3a (N2S) and 3b (N2S2), were synthesized by diacyl chloride–diamine sulfide coupling reactions followed by the tandem Claisen rearrangement of macrocycles 2a and 2b as precursors, respectively. The reactivity of the titled macrocycles with some transition and heavy metal ions was examined. The most salient feature of the reactions is the mercurated dihydrobenzofuran 4 derived from 3b and Hg(OAc)2. The X-ray crystal structures of 4 as well as 2a and 2b were revealed.