Base-Mediated Coupling Reactions of Benzenesulfonyl Azides with Proline: Synthesis of Proline-Derived Benzenesulfonamides

Abstract

Sulfonamides and lipids are widely found in natural products, bioactive substances, and pharmaceuticals. Here, we report N -sulfonylation and esterification of carboxylic acids in an environment-friendly one-pot tandem protocol involving 1,2-dichloroethane (DCE). Moreover, 1,8-diazabicyclo (5.4.0) undec-7-ene was necessary for this reaction as a strong base, which drives the reaction to completion. Although DCE is a very low activity reagent, it acts not only as a solvent but also as a reactant in the reaction. The β-chloroester contained in the reaction product can be easily dissociated to react with N, S, and O atoms, increasing the possibility for subsequent synthesis.

Synthesis of bridgehead-azacycles via dual C–N/C–C annulation of α-amino acids, aminals and maleimides

“…Secondary α-amino acids (proline, pipecolic acid and sarcosine) play a significant role in organic chemistry. 1–12 These core units are highly desirable due to their wide presence in pharmaceutical ingredients, natural products and bioactive molecules. 1 Additionally, these skeletal structures function as green organo-catalysts in a variety of asymmetric reactions and their use as ligands in metal catalysts is also well established.…”