Palladium catalysed cascade hydrostannylation-bis-cyclisation-intramolecular anion capture. Routes to bridged- and spiro-cyclic small and macrocyclic heterocycles
Palladiumcatalysedcascade hydrostannylation of terminal alkynes in α,ω-enynes at 0–25°C followed by bis-cyclisation initiated by insertion of Pd(0) into an aryl iodide at 100–110°C and terminating in an intramolecular Stille coupling provides a wide range of exo-methylene and membered spiro- and bridged-ring heterocycles.