Acetylides from alkyl propiolates as building blocks for C3 homologation.

Alkyl propiolates are reagents with a versatile reactivity profile that entirely remains in the C(3)-homologated product for further elaboration. To be effective, this C(3) homologation requires suitable methods for the generation of the acetylide anion that are compatible with both the conjugated ester and the electrophilic partner. Recent advances include catalytic procedures for the in situ generation of these acetylides in the presence of suitable electrophiles. Whereas the organometallic methods have brought stereoselectivity to these reactions, the organocatalytic methods laid the ground for new efficient domino processes that generate complexity.