Four-component 1,4-addition Ugi reaction catalyzed by the Schiff base derived from Tröger's base and BINOL

Substrate Switchable Pathway for Selective Construction of Bridged Dibenzo[b,f][1,5]diazocines and Bridged Spiromethanodibenzo[b,e]azepines

An operationally simple method for the synthesis of bridged dibenzo[b,f][1,5]diazocines and bridged spiromethanodibenzo[b,e]azepines exhibiting bridged eight-membered and seven-membered molecular architecture is reported. This unique approach is based on substrate selective mechanistic pathway, including an unprecendented aerial oxidation-driven mechanism for the synthesis of bridged spiromethanodibenzo[b,e]azepines. The reaction is highly atom economic, and in addition, it allows the construction of two rings and four bonds in a single operation under metal-free condition. The easy availability of β enaminone and ortho phathalaldehyde as starting materials and the simple operation make this approach suitable for the preparation of important dibenzo[b,f][1,5]diazocine and spiromethanodibenzo[b,e]azepine cores.

Base-Catalyzed, Solvent-Free Synthesis of Rigid V-Shaped Epoxydibenzo[b,f][1,5]diazocines

A novel method for the synthesis of epoxydibenzo[b,f][1,5]diazocines exhibiting a V-shaped molecular architecture is reported. The unique approach is based on unprecedented base-catalyzed, solvent-free autocondensation and cross-condensation of fluorinated o-aminophenones. The structure of the newly synthesized diazocines was confirmed independently by X-ray analysis and chiroptical methods. The rigidity of the diazocine scaffold allowed for the separation of the racemate into single enantiomers that proved to be thermally stable up to 140 °C. Furthermore, the inertness of the diazocine scaffold was demonstrated by performing a series of typical transformations, including transition metal-catalyzed reactions, proceeding without affecting the bis-hemiaminal subunit.