37441-76-2Relevant articles and documents
Regioselective Cyanation of Six-Membered N-Heteroaromatic Compounds Under Metal-, Activator-, Base- and Solvent-Free Conditions
Sarmah, Bikash Kumar,Konwar, Monuranjan,Bhattacharyya, Dipanjan,Adhikari, Priyanka,Das, Animesh
, p. 5616 - 5625 (2019)
A regioselective cyanation of heteroaromatic N-oxides with trimethylsilyl cyanide has been developed to obtain 2-substituted N-heteroaromatic nitrile without the requirement of any external activator-, metal-, base-, and solvent. The present protocol is a straightforward, one-pot heteroaromatic C?H cyanation process, and proceeds smoothly in conventional heating but also under microwave irradiation with shorter reaction times. This approach now allows access to a broad class of quinoline N-oxides and other heteroarene N-oxides with high to good yields and can also be scaled up to obtain gram quantities. Further application of this process was observed and utilized in late-stage cyanation of the anti-malarial drug quinine as well as transformation of the 2-cyanoazines to a series of biologically important molecules. Based on the experimental observations, a plausible mechanism has also been proposed highlighting the dual role of trimethylsilyl cyanide as a nitrile source and as an activating agent. (Figure presented.).
