Use of a "Structural Dummy" α-Silyl Substituent in Nazarov Cyclization: Expanding the Substrate Scope to Indanones and Bicyclic 2-Pyrones.

Aryl vinyl ketones, particularly those lacking an α-substituent, are among the most challenging substrates for Nazarov cyclization. We present a practical method to expand the scope of this reaction, enabling the efficient synthesis of indanones and bicyclic 2-pyrones. The use of an α-silyl substituent as a "structural dummy" enhances reactivity, and thus, the reaction proceeds under mild conditions. Notably, spontaneous desilylation during the reaction leaves the products with double-enolizable α-hydrogens, offering greater flexibility for functionalization at the α-position of the ketone.