Range Of Imines Research Articles

The Use of Aryl-Substituted Homophthalic Anhydrides in the Castagnoli–Cushman Reaction Provides Access to Novel Tetrahydroisoquinolone Carboxylic Acid Bearing an All-Carbon Quaternary Stereogenic Center

Novel aryl-substituted homophthalic acids were cyclodehydrated to the respective homophthalic anhydrides for use in the Castagnoli-Cushman reaction. With a range of imines, this reaction proceeded smoothly and delivered hitherto undescribed 4-aryl-substituted tetrahydroisoquinolonic acids with remarkable diastereoselectivity, good yields and no need for chromatographic purification. These findings significantly extend the range of cyclic anhydrides employable in the Castagnoli-Cushman reaction and signify access to a novel substitution pattern around the medicinally relevant tetrahydroisoquinolonic acid scaffold.

Expedient Organocatalytic Aza-Morita-Baylis-Hillman Reaction through Ball-Milling.

A ball-milling enabled tertiary amine catalyzed aza-Morita–Baylis–Hillman reaction is reported. The reaction process does not require solvent, has significantly shorter reaction times than previous methods and is reported on a range of imines and acrylate Michael acceptors across than 26 examples. A 12-fold scaled-up example is also reported as well as experimental comparisons to solution-based experiments and neat-stirred reactions.

Metal-Free Organocatalytic Oxidative Ugi Reaction Promoted by Hypervalent Iodine.

We report here a novel IBX-promoted oxidative coupling of primary amines and its utilization to Ugi reaction. Advantageously, the reaction could be carried out in choline chloride urea as a natural deep eutectic solvent. A range of imines and bisamides from pseudo-four-component oxidative Ugi reaction could be synthesized under mild and metal-free conditions. Advantageously, the oxidant (IBX) and solvent could be recycled up to five times with only a slight loss in activity.

ChemInform Abstract: Expedient Metal‐Free Synthesis of 1,3‐Oxazinen‐4‐ones.

AbstractStarting from 1‐benzoyl or 1‐acetylcyclopropane‐1‐carboxylic acid and a range of imines, the title compounds are synthesized in a high‐yielding operationally simple and rapid manner.

ChemInform Abstract: [3 + 2] Cycloaddition on Carbohydrate Templates: Stereoselective Synthesis of Pyrrolidines.

Pyrrolidine derivatives were prepared in high diastereoselectivities and good yields via a [3 + 2] cycloaddition of a tert-butyldimethylsilyl protected carbohydrate-based allene with a diverse range of imines. The subsequent removal of the carbohydrate auxiliary afforded a variety of pyrrolidines with excellent enantioselectivities (up to 99% ee). Selective reduction of the pyrrolidines further demonstrated the potential of this strategy.

A New Approach to Di- and Tetrasubstituted 2,3-Dihydropyridin-4(1H)-ones through Aza-Diels-Alder Reaction Promoted by Silicon Tetrachloride

Silicon tetrachloride promotes an aza-Diels-Alder reac- tion with a range of imines and Danishefsky's diene or an alkylated derivative, giving the desired products in good to excellent yields.

Imidazolinium Salts as Catalysts for the Aza‐Diels—Alder Reaction.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Imidazolinium salts as catalysts for the aza-Diels–Alder reaction

Various easily accessible imidazolinium salts have been found to be capable of catalysing an aza-Diels-Alder reaction with a range of imines and Danishefsky's diene, giving the desired products in good to excellent yields. The influence of the counter-anions on the reactivity has been explored. These salts could contribute to the field of metal-free catalysis/organocatalysis.