Carbon black intercalation compound as catalyst for unprecedent phase-transfer-catalyzed nucleophilic substitution (S_N2) in water

Carbon black intercalation compound was used for the first time as a heterogeneous phase-transfer-catalyst for S(N)2 type reaction of NaSCN with 4-nitrobenzyl bromide. The reaction proceeds in the presence of 5 mol% of catalyst with high efficiency in a liquid-liquid biphasic system (CHCl3/H2O), providing 98% conversion after only 4 h. Furthermore, an unprecedent efficient nucleophilic substitution was reported in water solution in the presence of the new catalyst, providing 95% yield in 8 h. The reaction is green, and the heterogeneous catalyst can be recovered and recycled without losing efficiency.