Metal-Free Direct Access toN-Sulfonyl Amidines from Sulfonamides and Secondary Amines Involving Tandem C–N Bond Formations

Abstract

We report a mild and efficient metal-free one-pot procedure for the synthesis of N-sulfonyl amidines via the direct reaction of sulfonamides with secondary amines without using any additives. A wide range of substrates with variety of functional groups is well tolerated under the reaction conditions. Preliminary mechanistic studies indicate that the secondary amine plays a dual role as a C1 source of the amidine group and an aminating agent. Synthetic utility of this method is shown in the late-stage functionalization of drug molecules on the gram scale.

Mechanochemical Metal‐free N‐Sulfonyl Transfer Reaction: Expedient Synthesis of N‐Sulfonyl Amidines

“…Additional references cited within the Supporting Information. [51][52][53][54][55][56] Author Contributions S. G. and S. M. synthesized the compounds, M. R., J. J. and S. Y. had performed the computational study, S. S. conceptualized the project and wrote the manuscript.…”

Visible-Light-Induced Metal- and Photocatalyst-Free Radical Cascade Cyclization of Cinnamamides for Synthesis of Functionalized Dihydroquinolinones

“…16 Moreover, expensive iridium or ruthenium catalysts are required, which greatly compromise the cost effectiveness and environmental safety. To overcome these limitations and support our continuing efforts 17 in using HIRs in metal-free sustainable chemical transformations, we describe herein a visible-lightpromoted decarboxylative radical cascade cyclization strategy using readily accessible, stable, and nontoxic α-oxocarboxylic acids as acyl radical precursors and cinnamamides as the radical acceptors for the sustainable synthesis of functionalized dihydroquinolinones. To the best of our knowledge, this photocatalyst-free visible-light-driven 6-endo-trig radical cascade cyclization strategy in the presence of iodobenzene diacetate (PIDA) has not been reported so far for the preparation of medicinally important dihydroquinolinones.…”

Electrochemically Promoted Three-Component Reaction to N-Sulfonyl Amidines

“…Due to their wide occurrence and importance of synthesizing N -sulfonyl amidines, these methods for the synthesis of N -sulfonyl amidine are of high interest. However, these reported methods often require the utilization of metal catalysts, potentially explosive sulfonyl azides, environmentally unfriendly solvents, and even stoichiometric oxidants . Electrochemical or visible-light-promoted reactions represent a straightforward and practical strategy to assemble N -sulfonyl amidine moieties (Scheme a).…”