Direct Preparation of 7‐Allyl‐ and 7‐Arylindolines

Addition of allyl halides to the organolithium species derived from lithiation of N‐tert‐butoxycarbonylindoline with sec‐butyllithium (sec‐BuLi) and tetramethylethylenediamine (TMEDA) occurs regioselectively by SN2 allylation. In contrast, the organolithium species can be transmetalated to the mixed zinc cuprate that undergoes regioselective SN2′ allylations. Transmetalation to the organozinc chloride allows a Negishi‐type cross‐coupling reaction with aryl bromides using palladium catalysis with triphenylphosphine (PPh3) as ligand. The chemistry was applied to a very short synthesis of 7‐prenylindole and of the alkaloid vasconine.