A reversible safety-catch method for the hydrogenolysis of N-benzyl moieties
摘要:
The benzyl groups of beta-hydroxy-N-benzyl sulfonamides are labile toward hydrogenolysis-unlike N-benzyl sulfonamides lacking the beta-hydroxy moiety. We find that N-acyl-N-benzyl sulfonamides undergo hydrogenolysis under very mild conditions. Based upon these observations, we developed a reversible safety-catch method using tert-butoxycarbonyl moieties to activate N-benzyl sulfonamides toward hydrogenolysis. We also explored the utility of the safety-catch activation method for other nitrogen-based functionality such as N-benzyl carboxamides, imides, and related functionality. (C) 2004 Elsevier Ltd. All rights reserved.
Photo-induced synthesis of β-sulfonyl imides from carboxylic acids
作者:Linwei Zeng、Jian Jin、Jixiao He、Sunliang Cui
DOI:10.1039/d1cc02559g
日期:——
A photo-induced imidation process of carboxylic acids is described. Numerous carboxylic acids could convert to β-sulfonyl imides in the presence of N-sulfonyl ynamides under visible light irradiation. Control experiments and mechanistic studies demonstrate that this imidation process involves a hydroacyloxylation/radical rearrangement cascade. This protocol represents a direct imidation method from
Manganese-Catalyzed <i>N</i>-Alkylation of Sulfonamides Using Alcohols
作者:Benjamin G. Reed-Berendt、Louis C. Morrill
DOI:10.1021/acs.joc.9b00203
日期:2019.3.15
An efficient manganese-catalyzed N-alkylation of sulfonamides has been developed. This borrowing hydrogen approach employs a well-defined and bench-stable Mn(I) PNP pincer precatalyst, allowing benzylic and simple primary aliphatic alcohols to be employed as alkylating agents. A diverse range of aryl and alkyl sulfonamides undergoes mono-N-alkylation in excellent isolated yields (32 examples, 85% average
The invention relates to substituted phenoxyacetic acids (I) as useful pharmaceutical compounds for treating respiratory disorders, pharmaceutical compositions containing them, and processes for their preparation.
Diverse Reactions of Sulfonyl Chlorides and Cyclic Imines
作者:Jing Liu、Shili Hou、Jiaxi Xu
DOI:10.1080/10426507.2011.608097
日期:2011.12.1
6-dihydro-4H-oxazines and thiazines, 4,5-dihydro-3H-benzo[c]azepine, and 3,4-dihydroisoquinoline, to produce diverse products instead of β-sultam derivatives. The results indicate that alkanesulfonyl chlorides react with cyclic imines to generate N-alkanesulfonyl cyclic iminium ions, which are attacked by nucleophiles, such as water and chloride anion, in the reaction systems, affording addition products
Keteniminium‐Driven Umpolung Difunctionalization of Ynamides
作者:Shubham Dutta、Shengwen Yang、Rajeshwer Vanjari、Rajendra K. Mallick、Vincent Gandon、Akhila K. Sahoo
DOI:10.1002/anie.201915522
日期:2020.6.26
synthesis of novel triaryl‐substituted enamides is described. This transformation represents the first example of an umpolung regioselective unsymmetrical syn ‐1,2‐diarylation/aryl‐olefination of ynamides. The aryl moieties of the diazonium salt (electrophile) and boronic acid (nucleophile) are explicitly incorporated in the electrophilic α‐ and nucleophilic β‐position, respectively, of the ynamide