(and the side products 5a) was identical in yield and enantioselectivity in the Ar atmosphere glovebox (for example, in the repetition of entry 1, Table ). In addition, methyl 3-hydroxy-2-naphthoate 2w was a poor substrate in the current reaction, producing no 3dw and only giving 5w (62%) as a racemate. Clearly, the current indolylnaphthol coupling of 1d has distinct mechanism from the previous aerobic BINOL coupling.