From Isocyanides to Iminonitriles via Silver-mediated Sequential Insertion of C(sp)-H Bond.

Heterocycles are prevalent constituents of many marketing drugs and biologically active molecules to meet modern medical challenges. Isocyanide insertion into C(sp)-H bonds is challenging especially for the construction of quaternary carbon centers. Herein, we describe an efficient strategy for the synthesis of α-iminonitrile substituted isochromans and tetrahydroisoquinolines (THIQs) with quaternary carbon centers through silver-triflate-mediated sequential isocyanide insertion of C(sp)-H bonds, where isocyanide acts as the crucial "CN" and "imine" sources.

Copper nitrate: a privileged reagent for organic synthesis.

Copper has been explored as an ideal candidate for replacing noble metals in organic synthesis, especially for practical large scale preparation. Recent decades have witnessed the renaissance and improvement of copper-catalyzed and copper-mediated organic reactions. Copper nitrate is a common inorganic copper salt which has been proved to be a ubiquitous reactant in organic synthesis due to its commercial availability, stability, inexpensiveness and environmentally benign nature.