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).
Polycyclic benzo-δ-phosphonolactams were synthesized from readily available ethyl arylmethylphosphonochloridates and dibenzo[b,f][1,4]oxazepines via one-pot [4+2] annulation.
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 have successfully developed a silver-free Rh(III)-catalyzed redox-neutral regioselective [3+2]-spiroannulation of dibenz(ox)azepines and ynones to access dibenz(ox)azepines containing α-aroyl spiro-indenamines.
A Rh(II)/Brønsted acid catalyzed [4 + 3] annulation of diazoenals and 3-substituted 2-oxindoles gave direct access to biologically important [1,3]oxazepino[3,2-a]indole derivatives.