Synthesis of C60-fused tetrahydrothiophene derivatives via nucleophilic cycloaddition of thiocyanates

Abstract

Nucleophilic cycloaddition of thiocyanates 1a–e with C₆₀ in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene afforded C₆₀-fused 2-iminotetrahydrothiophene derivatives 2a–e and methanofullerenes 3a–d. The product distributions were highly sensitive to the substrates employed. The 2-iminotetrahydrothiophene derivatives 2a–e could be further manipulated by hydrolysis and acetylation to give 2-oxotetrahydrothiophene derivatives 4a–e and 2-acetamidotetrahydrothiophene derivatives 5a–e. A possible reaction mechanism for the formation of products 2a–e and 3a–d was proposed.