An electrophilic thiocyanation/ipso-cyclization leading to spirocyclohexadienones

Me3SiBr-promoted cascade electrophilic thiocyanation/cyclization of ortho-alkynylanilines to synthesize indole derivatives

“…Based on the literature, 11 we proposed a possible reaction mechanism as shown in Scheme 3. First, the electrophilic thiocyanation reagent NTS is activated by the Lewis acid Me 3 SiBr and it reacts with the substrate 1a to form onium ion A .…”

Electrophilic Halospirocyclization of N-Benzylacrylamides to Access 4-Halomethyl-2-azaspiro[4.5]decanes

“…In recent years, the hypervalent iodine-mediated, metal-reagent-facilitated, light-induced, and electrochemical spirocyclization for the construction of azaspiro[4.5]­decanes has attracted more and more attention. Moreover, electrophilic spirocyclization is also a simple and efficient pathway for the synthesis of azaspiro[4.5]­decanes . Organic halides are one of the most common and useful organic compounds, and their synthesis and transformation are of great significance .…”

Copper(i)-catalyzed electrophilic thiocyanation/dearomatization/spirocyclization of benzofurans to synthesize benzannulated spiroketals

“…10 Among these, electrophilic thiocyanation has undergone substantial development in recent years, assisted by the discovery of diverse electrophilic N -thiocyanato reagents. 11 In pursuit of the electrophilic reaction chemistry of these reagents toward unsaturated bonds (Scheme 1c), 12 herein, we report the thiocyanation-triggered dearomatization/cyclization of benzofurans giving thiocyanated spiroketals (Scheme 1d).…”