Many natural products and synthetic pharmaceuticals contain heterocyclic groups, which often play an essential role in their biological activity [1]. Cyanogen halides have been widely used in the preparation of nitrogen- containing heterocycles via a double attack by the nitrogen and another heteroatom nucleophile (eg O, S, N); how- ever they suffer many drawbacks, including high volatility and high toxicity [2]. In addition, cyanogen bromide reacts readily with ...
