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

Abstract

1,3‐Dipolar cycloaddition between nonstabilized azomethine ylides and N‐sulfonylimines has been developed, providing practical access to mono‐N‐sulfonylimidazolidines. The enhanced reactivity of N‐sulfonylimines as dipolarophiles towards azomethine ylides largely eliminated possible Michael addition and favored 1,3‐dipolar cycloaddition. Our approach could complement commonly practiced strategies for protection of imidazolidines. Furthermore, nucleophile‐dependent ring cleavage of N‐sulfonylimidazolidines produced synthetically useful mono‐N‐sulfonyl‐1,2‐diamines, which are otherwise difficult to obtain. Ring cleavage accompanied by CH2 extrusion, yielding mono‐N‐sulfonyl‐1,2‐diamines, occurred on treatment with TBAF, whereas N‐methylated derivatives of N‐sulfonyl‐1,2‐diamines were produced on treatment with LAH.

Unexpected ring-opening of 2,3-dihydropyridines

“…Sulfonylimines have been described recently as important reagents and intermediates for the syntheses of heterocycles [1][2][3], heterocyclic arrangements [4], cycloadditions [5,6] and asymmetric Friedel-Crafts reactions [7] as well as for the synthesis of natural products [8,9]. They were investigated for their antimicrobial [10,11], herbicidal [12,13], and anticancer [14] activities.…”

“…6 -thia-5-azabicyclo[2.2.2]oct-7-en-2,2-dione (Reaction of 862 mg of 1c (4.48 mmol) in 39 cm 3 of CH 2 Cl 2 with 539 mg of methanesulfonyl chloride (4.70 mmol) in the presence of 1.36 g of TEA(13.…”

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

“…14 Notably, the use sulfamidate 15 , a cyclic N-sulfonylimine, has been used to prepare interesting heterocyclic scaffolds. Sulfamidate is transformed into a fused heterocycle using a Michael addition 16 , cycloaddition [17][18][19][20][21][22] , arylation [23][24][25] , alkenylation [26][27][28] , or alkynylation 26 strategy by leveraging electrophilicity of cyclic N-sulfonylimines (Scheme 1).…”

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

“…14 Notably, the use sulfamidate 15 , a cyclic N-sulfonylimine, has been used to prepare interesting heterocyclic scaffolds. Sulfamidate is transformed into a fused heterocycle using a Michael addition 16 , cycloaddition [17][18][19][20][21][22] , arylation [23][24][25] , alkenylation [26][27][28] , or alkynylation 26 strategy by leveraging electrophilicity of cyclic N-sulfonylimines (Scheme 1). Scheme 1: Strategy to explore N-sulfonylimine reactivity towards multicomponent reaction However, among reported synthetic strategies, construction of direct C-C bond between the imine carbon and the (het)aromatic partner is underrepresented in the literature.…”