Organocatalyzed Asymmetric Tandem Intramolecular oxa‐Michael Addition/Electrophilic Thiocyanation: Synthesis of Chiral α‐ Thiocyanato Flavanones

Organophotocatalytic Remote Thiocyanation Reaction via Ring-Opening Functionalization of Cycloalkanols

The remote C(sp3)-SCN bond formation via ring-opening functionalization of cycloalkanols with N-thiocyanatosaccharin as the precursor of SCN radicals and pyrylium salt as the organic photocatalyst under visible light has been developed. Thus, various terminal keto thiocyanates were prepared without transition metals and oxidants in moderate to good yields. The simplicity, wide substrate scope and mild conditions feature its synthetic application capability.

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

A Lewis acid-promoted electrophilic thiocyanation/cyclization of ortho-alkynylanilines for the synthesis of indole derivatives has been developed. The reaction utilizes Me3SiBr as the Lewis acid and N-thiocyanatosuccinimide as the thiocyanation reagent. A series of 2-aryl-3-thiocyanato indoles were prepared in moderate to high yields under mild conditions without metals and oxidants. It provides an efficient protocol for the construction of the indole skeleton and C-SCN and C-N bonds in one step as well.

Asymmetric Hydrogenation by Relay Catalysis with FLPs and CPAs: Stereodivergent Synthesis of 3-Substituted Flavanones

To access flavanones bearing two contiguous stereogenic centers, a metal-free asymmetric hydrogenation of racemic 3-alkylidene flavanones has been developed by relay catalysis with achiral FLPs and chiral phosphoric acids, which represents a successful detour for the challenging hydrogenation of 3-substituted flavones. A wide range of trans- and cis-flavanones were obtained in high yields and ≤97% ee.