Telluride-Based Pillar[5]arene: A Recyclable Catalyst for Alkylation Reactions in Aqueous Solution.

Abstract

The syntheses of previously unknown sulfide- and telluride-pillar[n]arenes are reported here. These macrocycles, among others, were tested as catalysts for alkylation reactions in aqueous solutions. Telluride-pillar[5]arene (P[5]-TePh) showed the best performance, emulating the behavior of the methyltransferase enzyme cofactor S-adenosyl-l-methionine. Using 1.0 mol % of P[5]-TePh, benzyl bromides reacted with NaCN/NaN₃ in water, yielding organic nitriles/azides. The catalyst was recycled and efficiently reused for up to six cycles. ¹H NMR experiments indicate a possible interaction between the substrate and P[5]-TePh's cavity.