Reactions of Nitrile Imines with Thiohydantoin Derivatives: Unexpected Chemoselectivity of the 1,3-Dipolar Cycloaddition: Preferential Addition of C=C rather than C=S Bonds.

ABSTRACT: Nitrile imines are highly reactive 1,3-dipoles that have found extensive application in [3 + 2]-cycloaddition reactions, offering an efficient approach to introducing pyrazoline and pyrazole motifs into biologically active compounds. In this study, we explore the reactivity of nitrile imines using thiohydantoin derivatives as dipolarophiles, which feature both carbon-carbon and carbon-sulfur bonds suitable for cycloaddition. Typically, carbon-sulfur (C=S) bonds are considered "super dipolarophiles" in nitrile imine cycloaddition reactions. However, we observed an unexpected chemoselectivity in the reaction between nitrile imines and 5-methylidene-2-thiohydantoin, where the reaction surprisingly favored the carbon-carbon (C=C) bond over the expected carbon-sulfur (C=S) bond. Our findings de

SUBMITTER: Filkina ME 

PROVIDER: S-EPMC12423912 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature