10.1021/jo00348a030
The research focused on the acid catalysis of sulfamate group transfer reactions, which are of interest as a mild sulfonation method. The study aimed to investigate both intermolecular and intramolecular catalysis of sulfonate group transfer from sulfamates and to demonstrate the differences in these mechanisms. The researchers conducted experiments involving the hydrolysis of N-(2-carboxyphenyl)sulfamic acid and other related compounds, using various chemicals such as chlorosulfonic acid, 1-naphthylamine, Na2CO3, and dioxane/water as reaction media. They also utilized deuterium oxide for solvent isotope effects and performed kinetic measurements to analyze the reactions. The conclusions drawn from the study indicated that the carboxyl group participates in the hydrolysis of N-(2-carboxyphenyl)sulfamic acid, and that proton transfer from the carboxylic acid is concerted with sulfamate group transfer to water. The research also excluded neighboring nucleophilic attack on sulfur by the carboxylate group and demonstrated intermolecular catalysis by carboxylic acids in the hydrolysis of N-(1-naphthy1)sulfamic acid. The mechanism involved preequilibrium protonation of the nitrogen followed by nucleophilic attack on sulfur by the carboxylate anion, leading to the hydrolysis of the compound.
10.1002/bkcs.11755
The study presents a synthetic method for the preparation of ethyl 4-(alkyl or arylsulfonamido)-2-naphthoates, which are derivatives of 1-aminonaphthalene, 3-aminobenzofuran, and 3-aminobenzothiophene. These compounds are significant due to their presence in biologically active molecules used in cancer treatment and as inhibitors for various enzymes. The synthesis involves a copper(I)-catalyzed cyclization reaction of ethyl (E)-α-ethynyl-β-aryl-α,β-unsaturated esters with N-sulfonyl azides in the presence of 2,6-lutidine in THF at 60°C for 3 hours. This method efficiently produces a wide range of the aforementioned derivatives with the release of molecular nitrogen. The chemicals used in the study include ethyl (E)-α-ethynyl-β-aryl-α,β-unsaturated esters as starting materials, N-sulfonyl azides as reactants, 2,6-lutidine as a base, and copper(I) as a catalyst, all serving specific roles in the cyclization reaction to form the desired aminonaphthalene and related derivatives.
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