RuCl3•3H2O Catalyzed Reactions: Facile Synthesis of Bis(indolyl)methanes under Mild Conditions

RuCl3 center dot 3H(2)O was found to be an effective catalyst for reactions of indoles, 2-methylthiophene, and 2-methylfuran with aldehydes to afford the corresponding bis(indolyl)methanes, bis(thienyl)methanes, and bis(fur-2-yl)methanes in moderate to excellent yields. Experimental results indicated that mono(indolyl) methanol is not the reaction intermediate under these reaction conditions.