N-Prop-2-ynylmaleimide. Application to Sequential One-pot Rh(I) Catalysed [2+2+2]-Alkyne Cyclotrimerisation–Imine Cycloaddition

Rh(I) catalysed [2+2+2]-cyclotrimerisation of 1,6-diynes with monoynes in combination with stereospecific thermal or Ag(I) catalysed aldimine→(metallo) azomethine ylide→cycloaddition cascades affords rapid access to complex heterocyclic benzene derivatives in one-pot processes with the generation 5 new bonds, 4 stereocentres and 3 rings.