Selective Gold-Catalysed Synthesis of Cyanamides and 1-Substituted 1<i>H</i>
-Tetrazol-5-Amines from Isocyanides
作者:Karel Škoch、Ivana Císařová、Petr Štěpnička
DOI:10.1002/chem.201803252
日期:2018.9.18
The newly discovered gold‐catalysed reaction of isocyanides with hydrazoic acid generated in situ from trimethylsilyl azide and methanol (or, alternatively, from NaN3/AcOH) produces either cyanamides or 1‐substituted 1H‐tetrazol‐5‐amines, depending on the amount of available HN3. The reaction proceeds selectively and in generally high yields of either product, thus providing a particularly convenient
versatile synthetic methodology for the construction of tetrazoles and guanidines in the presence of an eco-friendly, inexpensive, easily available iron reagent. Aromatic thioureas with electron-donating substituents produced their respective target products in quantitative yield. In contrast, when electron-withdrawing substituted aromatic thioureas were used, the expected products were obtained in reduced