Highly Selective Synthesis of Seven-Membered Azaspiro Compounds by a Rh(I)-Catalyzed Cycloisomerization/Diels-Alder Cascade of 1,5-Bisallenes

The synthesis of spiro compounds featuring seven- and six-memberedrings in the spirobicyclic motif is successfully achieved through a cascade processencompassing a rhodium(I)-catalyzed cycloisomerization followed by a highlyselective Diels-Alder homodimerization. The scope of the reaction is analyzed based on a series of synthetic substrates, and control experiments and DFT calculations led us to justify the exquisite degree of selectivity observed

Automated summary

The synthesis of spiro compounds with seven- and six-membered rings was achieved through a cascade process involving a rhodium(I)-catalyzed cycloisomerization and a highly selective Diels-Alder homodimerization. The scope of the reaction was analyzed using synthetic substrates, and control experiments and DFT calculations were used to explain the observed degree of selectivity.