Sulfur-containing stable five-membered “cycloallene” complexes: 1-thia-2-zircona- and 1-thia-2-titanacyclopenta-3,4-dienes

Abstract

Stable five-membered metallacyclic allenes that contain a sulfur atom were synthesized and structurally characterized. Low-valent zirconocene and titanocene reacted with alkynylthioamides to afford 1-thia-2metallacyclopenta-3,4-diene compounds in moderate to excellent yields. The molecular structure of the zirconium complexes indicated their cycloallene structure, while an η 2 -alkyne-coordinated structure might be more responsible for the titanium complexes. Hydrolysis of the compounds gave the corresponding (Z)-alkenylthioamides predominantly. Deuterolysis resulted in >99% D incorporation. Fig. 1 Stable five-membered metallacycloallenes.compounds as well as other group 4 metal complexes. We herein report the synthesis and structure of sulfur-containing zirconacycloallenes and titanacycloallenes.This journal is

Copper‐Catalyzed Synthesis of Alkynyl Thioamides: An Efficient Thioacylation of Alkynes

“…Thioamides react with diazo compounds to give pyrazole rings, [10] the cyclization of thioamide can also give heterocyclic compounds. [11] In addition, thioamides can be used to form pentamembered carbon compounds with transition metals, [12] as well as ligand in coordination chemistry (Figure 1, D). [13][14][15][16][17] Therefore, the development of efficient synthesis of functionalized thioamides has been the pursuit of organic chemists in recent years.…”