Reactions of 9H-Fluorene-9-thione with (Trimethylsilyl)- diazomethane*

The [3+2]-cycloaddition of (trimethylsilyl)diazomethane (7) with 9H-fluorene-9-thione (1) at –60°C yields the spirocyclic 2,5-dihydro-5-trimethylsilyl-1,3,4-thiadiazole 10, which eliminates nitrogen at room temperature to give the 1,4-dithiane derivative 13 by dimerization of the intermediate fluorenethione (trimethylsilyl)methanide (11). This thiocarbonyl ylide can be trapped by 1 to give the 2-trimethylsilyl-1,3-dithiolane 14 via [3+2]-cycloaddition. Furthermore, the 1,3-dipole 11 undergoes successfully [3+2]-cycloadditions with the C=S group of the phosphonyldithioformate 15 as well as with the C=C dipolarophiles maleic anhydride (18a) and N-(cyclohexyl)maleimide (18b). The structures of 13 and 14 have been established by X-ray crystallography. Posted at the Zurich Open Repository and Archive, University of Zurich ZORA URL: https://doi.org/10.5167/uzh-50663 Published Version Originally published at: Mloston, G; Urbaniak, K; Linden, A; Heimgartner, H (2007). Reactions of 9H-Fluorene-9-thione with (Trimethylsilyl)diazomethane. Polish Journal of Chemistry, 81(11):1849-1860. Re ac tions of 9H-Fluorene-9-thione with (Trimethylsilyl)dia zo me thane by G. Mlostoñ, K. Urbaniak, A. Lin den and H. Heimgartner Sec tion of Heteroorganic Com pounds, Uni ver sity of £ódŸ, Narutowicza 68, PL-90-136 £ódŸ, Poland In sti tute of Or ganic Chem is try, Uni ver sity of Zu rich, Winterthurerstrasse190, CH-8057 Zu rich, Switzerland **e-mail: [email protected]; [email protected] (Re ceived April 19th, 2007) The [3+2]-cycloaddition of (trimethylsilyl)dia zo me thane (7) with 9H-fluorene-9-thione (1) at –60°C yields the spirocyclic 2,5-dihydro-5-trimethylsilyl-1,3,4-thiadiazole 10, which elim i nates ni tro gen at room tem per a ture to give the 1,4-dithiane de riv a tive 13 by dimerization of the in ter me di ate fluorenethione (trimethylsilyl)methanide (11). This thiocarbonyl ylide can be trapped by 1 to give the 2-trimethylsilyl-1,3-dithiolane 14 via [3+2]-cycloaddition. Fur ther more, the 1,3-di pole 11 un der goes suc cess fully [3+2]cycloadditions with the C=S group of the phosphonyldithioformate 15 as well as with the C=C dipolarophiles maleic an hy dride (18a) and N-(cyclohexyl)maleimide (18b). The struc tures of 13 and 14 have been es tab lished by X-ray crys tal log ra phy.