Synthesis of Mono-N -sulfonylimidazolidines by a 1,3-Dipolar Cycloaddition Strategy, as an Alternative to Selective N -Sulfonylation, and Their Ring Cleavage To Afford 1,2-Diamines

Electrochemical Generation of a Nonstabilized Azomethine Ylide: Access to Substituted N-Heterocycles

Azomethine ylides are fascinating 1,3-dipoles for [3 + 2] cycloaddition reactions toward the construction of N-heterocycles. Herein, an efficient and environmentally benign electrochemical approach for the generation of a nonstabilized azomethine ylide has been established under metal-free and external oxidant-free conditions. The resulting 1,3-dipole undergoes a [3 + 2] cycloaddition reaction with olefins. This electrosynthetic methodology indulges a straightforward and facile approach for the construction of substituted pyrrolidines.

Unexpected ring-opening of 2,3-dihydropyridines

The reaction of 2,3-dihydropyridines with sulfonyl halides surprisingly yielded open chain dienes with sulfonylimine structure. The products were specific out of several possible isomers and, therefore, a separation of isomers was not necessary. All new compounds were characterized using FT-IR spectroscopy, HRMS, and NMR spectroscopy. A bicyclic by-product from the reaction of a 2,3-dihydropyridine with mesyl chloride was isolated and its structure elucidated using a single X-ray crystal analysis. Some biological activities, like antimicrobial and cytotoxic properties were investigated.

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Accelerated Reactivity Mechanism and Interpretable Machine Learning Model of N-Sulfonylimines toward Fast Multicomponent Reactions

We introduce chemical reactivity flowcharts to help chemists interpret reaction outcomes using statistically robust machine learning models trained on a small number of reactions. We developed fast N-sulfonylimine multicomponent reactions for understanding reactivity and to generate training data. Accelerated reactivity mechanisms were investigated using density functional theory. Intuitive chemical features learned by the model accurately predicted heterogeneous reactivity of N-sulfonylimine with different carboxylic acids. Validation of the predictions shows that reaction outcome interpretation is useful for human chemists.

Five-membered cyclic sulfamidate imines: versatile scaffolds for organic synthesis

In recent years, five-membered ring cyclic sulfamidate imines (5H-1,2,3-oxathiazole 2,2-dioxides) have received increasing attention as useful precursors for the stereoselective synthesis of many valuable heterocycles. Bearing a reactive N-sulfonyl imine moiety as part of the stereodefined skeleton, this sulfamidate imine platform has been utilised as a substrate in many reactions, including nucleophilic additions and reductions, to prepare highly functionalised cyclic sulfamidates. In addition, cyclic sulfamidate imines can also readily participate as nucleophiles in many chemical transformations, owing to the acidic proton(s) adjacent to the imine moiety. This short review highlights recent developments involving cyclic sulfamidate imines, including their synthesis and reactivity, with a focus on stereoselective processes.