Base‐promoted [4+3] Cycloadditions of N‐Thioacylimines with α‐chlorohydroxamates: Construction of 1,3,5‐Thiadiazepin‐6(7H)‐one Derivatives

A metal‐free base‐promoted [4+3] cycloaddition reaction of N‐thioacyl imines in situ generated from α‐amido sulfones with α‐chlorohydroxamates is described. The reaction facilitates the straightforward synthesis of 1,3,5‐thiadiazepin‐6(7H)‐one derivatives in 44~90% yields. Moreover, a gram‐scale reaction and product transformation were conducted, which further increased the diversity of products.