Synthesis of N-arylphthalimides catalyzed by 1,4-diazabicyclo[2,2,2]octane [DABCO] in solventless system

Two novel telluroniobates with efficient catalytic activity for the imidation/amidation reaction

We present the synthesis and catalytic properties of two novel telluroniobates {Te₁₅Nb₂₁} and {Te₁₀Nb₁₄}. {Te₁₅Nb₂₁} is the first trimeric telluroniobate with the largest number of tellurium atoms in the Te-Nb system. Besides, both clusters exhibit excellent catalytic activity in the amidation reactions of anhydrides and amines, and cyclic imides and bi-amides can be controllably synthesized, which represents a breakthrough in the catalysis of polyoxoniobates.

Solvent-Free L-Proline Catalysed Condensation of Ethyl Cyanoacetate with Aldehydes

Solvent-free Knoevenagel condensation of ethyl cyanoacetate with aromatic aldehydes, catalysed by environmentally friendly silica gel supported L-proline under microwave irradiation is studied.

Non-thermal polyimidization reaction using base–ionic liquid medium as a dual catalyst–solvent

A one-step synthesis of PMDA–ODA polyimide at ambient temperature was reported for the first time, in which a polyimidization reaction was rapidly accomplished in 99% yield in an imidazolium-based ionic liquid containing a non-nucleophilic base.

Versatile and sustainable synthesis of cyclic imides from dicarboxylic acids and amines by Nb2O5 as a base-tolerant heterogeneous Lewis acid catalyst

Catalytic condensation of dicarboxylics acid and amines without excess amount of activating reagents is the most atom-efficient but unprecedented synthetic method of cyclic imides. Here we present the first general catalytic method, proceeding selectively and efficiently in the presence of a commercial Nb2 O5 as a reusable and base-tolerant heterogeneous Lewis acid catalyst. The method is effective for the direct synthesis of pharmaceutically or industrially important cyclic imides, such as phensuximide, N-hydroxyphthalimide (NHPI), and unsubstituted cyclic imides from dicarboxylic acid or anhydrides with amines, hydroxylamine, or ammonia.