Enantioselective Ruthenium-Catalyzed Allenylidene-Ene Cyclization

Significance

The authors have applied their previously reported methodology (Y. Nishibayashi et al. J. Am. Chem. Soc. 2004, 126, 16066) towards a Ru-catalyzed intramolecular cyclization of allenylidene-ene compounds. The products are desirable enantioenriched heterocycles, and the level of diastereoselectivity depends on the substituents (R^¹ and R^² above).