Cs2CO3 catalyzed rapid and efficient conversion of amines into sulfonamides; Alcohols and phenols into sulfonic esters
A simple and efficient method has been developed for the sulfonylation of several amines, alcohols, and phenols by p-toluenesulphonylchloride (p-TsCl) in the presence of catalytic amount of Cs2CO3 at 25C to obtain sulfonamides and sulfonic esters in very good yields. Cs2CO3 has been found to be highly efficient catalyst. Taylor & Francis Group, LLC.
Reddy, M. B. Madhusudana,Pasha
experimental part
p. 1867 - 1875
(2011/10/11)
Hg cathode-free electrochemical detosylation of N,N-disubstituted p-toluenesulfonamides: mild, efficient, and selective removal of N-tosyl group
Hg cathode-free electrochemical detosylation of N,N-disubstituted p-toluenesulfonamides was successfully carried out by a constant current electrolysis using an undivided cell equipped with a platinum cathode and a magnesium anode in the presence of an arene mediator. The deprotection proceeded efficiently and selectively under neutral and mild conditions with a stoichiometric amount of electricity without the use of an Hg cathode to obtain the corresponding secondary amines in good to excellent yields.
METHOD FOR DEPROTECTING ARYL OR ALKYL SULFONAMIDES OF PRIMARY OR SECONDARY AMINES
The invention relates to a method for removing an alkyl sulfonyl or aryl sulfonyl protecting group from a primary or secondary amine by contacting an alkyl sulfonamide or an aryl sulfonamide with a Stage 0 or Stage I alkali metal-silica gel material in the presence of a solid proton source under conditions sufficient to form the corresponding amine. The invention also relates to a method for removing an alkyl sulfonyl or aryl sulfonyl protecting group from a primary or secondary amine by a) reacting an alkyl sulfonamide or an aryl sulfonamide with a Stage 0 or Stage I alkali metal-silica gel material, and b) subsequently reacting the reaction product from step a) with an electrophile or a proton source. Preferred Stage 0 or Stage I alkali metal-silica gel materials include Na, K2Na, and Na2K.
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Page/Page column 8
(2009/12/24)
Alkali metals in silica gel (M-SG): A new reagent for desulfonation of amines
(Chemical Equation Presented) A novel method for the desulfonation of secondary amines is described. Alkali metals absorbed into nanostructured silica (M-SG) were found to be useful solid-state reagents for the desuffonation of a range of N,N-disubstituted sulfonamides. M-SG reagents are room-temperature- stable free-flowing powders that retain the chemical reactivity of the parent metal, decreasing the danger and associated cost of using reactive metals.
Nandi, Partha,Redko, Mikhail Y.,Petersen, Kathryn,Dye, James L.,Lefenfeld, Michael,Vogt, Paul F.,Jackson, James E.
supporting information; experimental part
p. 5441 - 5444
(2009/06/18)
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