Intramolecular Anti ‐Carbolithiation of Alkynes: Stereo‐Directing Effect of Lithium‐Coordinating Substituents
Résumé
The stereochemical course of intramolecular carbolithiation of alkynes was, experimentally and computationally, investigated for the stereocontrolled preparation of alkylidene indenols. Reversal of syn-carbolithiation to anti-carbolithiation is observed in the presence of a lithium-chelating propargylic substituent. Electrophile trapping and domino process give access to tetrasubstituted compounds. Initial results on unprecedented enantioselective desymmetrizing carbolithiation are discussed.