Regioselective C₃Alkylation of Indoles for the Synthesis of Bis(indolyl)methanes and 3-Styryl Indoles

Abstract

Herein, we describe an efficient transition-metal-free regioselective C 3 alkylation of indoles for the synthesis of bis-(indolyl)methanes and 3-styryl indoles. Nitrobenzene is employed as the oxidant to oxidize the alcohols in the presence of a strong base and the reaction avoids the use of transition metals such as Ru and Mn. The protocol provides a favorable route to access biologically active compounds such as arundine, vibrindole A, and turbomycin B.

Photocatalytic Tandem Protocol for the Synthesis of Bis(indolyl)methanes using Cu-g-C3N4–Imine Decorated on TiO2 Nanoparticles under Visible Light Irradiation

“…Thus, the synthesis and functionalization of bis­(indolyl)­alkane derivatives have attracted significant attention, which led to many synthetic protocols. Although these strategies are useful, they are limited to specific classes of coupling partners in the presence of toxic metal salts, longer reaction times, low yields of products, high catalyst loadings, and high temperatures. − Alternatively, direct access to bis­(indolyl)­alkane derivatives from simple precursors such as alcohols would prove useful since they can be easily converted into aldehydes through oxidation reactions.…”