Chiral Brønsted acid catalyzed stereoselective addition of azlactones to 3-vinylindoles for facile access to enantioenriched tryptophan derivatives.

Syn-gled out: The syn diastereo- and enantioselective addition of azlactones to 3-vinylindoles was accomplished by using a chiral, binapthol-derived, Brønsted acid catalyst (see scheme). This method enables facile access to tryptophan derivatives with adjacent quaternary and tertiary stereogenic centers, which are potentially useful for the synthesis of peptidomimetics.