Facile entry into structurally diverse, privileged, (hetero)arene-fused N-alkoxy 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-ones

Palladium-Catalyzed Heteroannulation of Salicylamides with Propargyl Carbonates: Synthesis of 1,4-Benzoxazepin-5-ones

Herein, we report a palladium-catalyzed method to synthesize 1,4-benzoxazepin-5-ones using salicylamides and propargyl carbonates. The heteroannulation provides a wide range of products in good to excellent yields with broad functional group tolerance. In addition, H2O is used as a low-cost, abundant, and safe solvent, which is important in terms of sustainability.

Rare Medium-Sized Rings Prepared via Hydrolytic Imidazoline Ring Expansion (HIRE)

The hydrolytic imidazoline ring expansion (HIRE) methodology was extended to readily available tetracyclic [1,4]thiazepines as well as sulfoxide and sulfone analogs thereof. The reactions resulted in the facile formation of a rare medium-sized [1,4,7]thiazecine ring system that has an emerging utility in bioactive compound design. Comparing the HIRE rates for representative compounds in the three groups of substrates allowed drawing some generalizations about the substituent effects on the course of the reaction.

Structurally diverse arene-fused ten-membered lactams accessed via hydrolytic imidazoline ring expansion

A facile approach to hitherto unknown ten-membered ring systems via a hydrolytic imidazoline ring expansion (HIRE) is described. Medium-sized rings are scarce in the contemporary medicinal chemistry toolbox. The new HIRE strategy broadens the arsenal of synthetic methods to obtain such scaffolds.