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An effective approach for amino protection and construction of a seven-membered ring has been developed. The method uses imidazolium chloride to carry out the Michael addition reaction at low temperatures and perform amino deprotection or construction of a seven-membered ring at high temperatures.

A selective and practical bromine–metal exchange on bromoheterocyclics bearing substituents with an acidic proton under non-cryogenic conditions was developed by a simple modification of an existing protocol. Our protocol of using a combination of i-PrMgCl and n-BuLi has not only solved the problem of intermolecular quenching that often occurred when using alkyl lithium alone as the reagent for halogen–lithium exchange, but also offered a highly selective method for performing bromo–metal exchange on dibrominated arene compounds through chelation effect.

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Background and objective: As a key pharmacophore, cyano group widely exists in a variety of biologically active compounds. Besides, nitriles are also valuable intermediates for many common functional groups. in this current work, a new synthesis strategy was developed to obtain nitriles from aldehydes. Methods: Using commercially available aldehydes as raw materias, hydroxylamine hydrochloride as nitrogen source, the corresponding nitrile compounds were successfully synthesized by one-pot method through the promotion of imidazole hydrochloride. And it was characterized by 1H NMR, 13C NMR and mass spectrometry. Results: Various reaction conditions were applied in order to find an optimum and convenient procedure for the formation of nitriles. The highest yields (95%) was achieved using sulfolane as solvent, imidazole hydrochloride as promoter. Conclusion: In conclusion, we developed a new synthetic method for nitrile compounds from aldehydes. 27 examples of functionalized nitrile compounds have been synthesized in good to excellent yields. This methodology features that an environmentally benign imidazole hydrochloride replaces transition metal catalysts and oxidants required in conventional strategies to convert aldehydes to nitriles with good functional group tolerability. Further exploration of imidazole hydrochloride is ongoing in our laboratory.