Yttrium triflate-catalyzed efficient chemoselective S-benzylation of indoline-2-thiones using benzyl alcohols

A highly efficient yttrium triflate-catalyzed chemoselective S-benzylation of indolin-2-thiones using variously substituted benzyl alcohols has been developed for the synthesis of indole-based sulfides. This procedure presents a greener approach for the synthesis of S-alkylated indoles. The reaction condition is amenable to primary, secondary, and tertiary benzylic alcohols as the benzyl group donors.