Iron-Catalyzed Direct C3-Benzylation of Indoles with Benzyl Alcohols through Borrowing Hydrogen.

ABSTRACT

We present the coupling of primary and secondary benzyl alcohols with indoles to form 3-benzylated indoles and H2O that is catalyzed, for the first time, by a complex of earth-abundant iron. This transformation accommodates a variety of substrates and is distinguished by its operational simplicity, sustainability, high functional-group tolerance, and amenability to gram-scale synthesis. On the basis of the preliminary experimental observations, we propose that the reaction proceeds through a borrowing hydrogen process.