Synthetic strategies and diversification of dibenzo[1,5]diazocines

Dibenzo[1,5]diazocine scaffolds are present in a wide range of organic building blocks, for example in pharmaceuticals, materials and structural chemistry. However, the development of these structural frameworks has not received significant attention owing to limited synthetic protocols and strategies. Herein, a summary of the attractive synthetic approaches for the construction of dibenzo[1,5]diazocines, epiminodibenzo[1,5]diazocines and epoxydibenzo[1,5]diazocines developed over the past two decades is presented. The spectroscopic, synthetic mechanisms for the formation of the heterocyclic rings and remarkable structural features, including in the solid-state, are discussed.

Design and Synthesis of Imidazolium-Mediated Tröger's Base-Containing Ionene Polymers for Advanced CO2 Separation Membranes

It is highly desirable to integrate the CO2 solubility benefits of ionic liquids (ILs) in polymeric membrane systems for effective CO2 separations. Herein, we are exclusively exploring a series of four novel imidazolium-mediated Tröger's base (TB)-containing ionene polymers for enhanced CO2 separation. The two diimidazole-functionalized Tröger's base monomers synthesized from "ortho"- and "para"-substituted imidazole anilines were polymerized with equimolar amounts of two different aromatic and aliphatic comonomers (α,α'-dichloro-p-xylene and 1,10-dibromodecane, respectively) via Menshutkin reactions to obtain four respective ionene polymers ([Im-TB(o&p)-Xy][Cl] and ([Im-TB(o&p)-C10][Br], respectively). The resulting ionene polymers having halide anions were exchanged with [Tf2N]- anions, yielding a novel Tröger's base material [Im-TB(x)-R][Tf2N] or "Im-TB-Ionenes". The structural and physical properties as well as the gas separation behaviors of the copolymers of aromatic and aliphatic Im-TB-Ionenes have been extensively investigated with respect to the regiochemistry of imidazolium groups at the ortho and para positions of the TB unit. The imidazolium-mediated TB-Ionenes showed high CO2 solubility and hence an excellent CO2/CH4 permselectivity of 82.5. The Im-TB-Ionenes also displayed good thermal and mechanical stabilities.

CuI-catalyzed amination of Tröger's base halides: a convenient method for synthesis of unsymmetrical Tröger's bases

A convenient and efficient Ullmann type copper catalyzed amination method has been developed for direct amination of halogen substituted Tröger's base analogues.