We report an unexpected route for synthesizing pyrrole-fused dibenzoxazepines/thiazepines with high chemoselectivity via a pseudo-Joullié–Ugi reaction from cyclic imines with isocyanides and acetylenedicarboxylates under catalyst-free conditions.
Highly efficient asymmetric hydrogenation of dibenzo-fused azepines derivatives with chiral cationic Ru diamine catalysts has been developed, giving diverse chiral seven-membered N-heterocycles with excellent results (up to 99% yield and 99% ee).
A new two-step, one-pot synthesis of benzo[f][1,2]thiazepine 1,1-dioxides was developed based on a visible-light mediated aza Paternò–Büchi reaction and a Lewis acid catalyzed ring-expansion of azetidine.
An efficient visible-light-induced Staudinger [2 + 2] annulation reaction under catalyst-free conditions has been established, and tetracyclic dibenzo[b,f][1,4]oxazepine/thiazepine-fused β-lactams were synthesized with a broad substrate scope and high efficiency (37 examples, up to >99% yield).
We present a powerful, metal-free annulation that directly transforms α-CF3-styrenes into valuable fluorinated seven-membered heterocycles, including thiazepine and oxazepine frameworks.