Reactions of 3,5‐Diaryl‐1,2‐dithiolium Salts and 3,5‐Diaryl‐1,2,4‐dithiazolium Salts with Metal Cyclopentadienides

Abstract

Reaction of the 3,5-diaryl-l,2-dithiolium salts 2 with the metal cyclopentadienides 4 and 9 leads to the formation of the tricyclic compounds 6 and 10 via a ring-opened intermediate, which undergoes an intramolecular Diels-Alder cyclization. Compounds 6 and 10 rearrange by treatment with boron trifluoride-diethyl ether to the isomeric compounds 7 and 11. The structures 6f and 7f were confirmed by X-ray analysis. Condensation of the 3,5-diaryl-l,2,4-dithiazolium salts 3 with the metal cyclopentadienides 4 affords the tricyclic compounds 12, which do not rearrange by Lewis acid catalysis.