- Green and efficient synthesis of sulfonamides catalyzed by nano-Ru/Fe 304
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The environmentally benign synthesis of carbon-nitrogen bonds continues to be an active and challenging field of chemical research. Here, a novel, environmentally benign method for the direct coupling of sulfonamidesand alcohols is described. Despite the importance of sulfonamide deriva tives as intermediates in drug synthesis, till now such transformations are rarely known. For the first time a domino dehydrogenation-condensation-hydrogenation sequence of alcohols and sulfonamides has been realizedin the presence of a nanostructured catalyst. The magnetic property of the catalyst system allows for convenient isolation of the product and e fficient recycling of the catalyst. A variety of coupling reactions of benzylic alcohols and sulfonamides including various heterocycles were successfully realized, often with >80percent isolated yield. Advantageously, only one equivalent of the primary alcohol is consumed in the process. Mechanistic investigations of the competitive reactions of benzyl alcohol and d7-benzyl alcohol with p-toluenesulfonamide revealed a kinetic isotope effect (kH/kD) of 2.86 (±0.109) for the dehydrogenation of benzyl alcohol and 0.74 (±0.021) for the hydrogenation of N-benzylidene-p-toluenesulfonamide intermediate, which suggests dehydrogenation of the alcohol to be the rate determining step.
- Shi, Feng,Tse, Man Kin,Zhou, Shaolin,Pohl, Marga-Martina,Radnik, Joerg,et al.
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supporting information; experimental part
p. 1775 - 1779
(2009/07/25)
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- Copper-catalyzed alkylation of sulfonamides with alcohols
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Water is the only by-product in an efficient and atom-economical Cu(OAc)2-catalyzed coupling of alcohols with sulfonamides (see proposed mechanism; Ts= p-toluenesulfonyl). It was discovered that bissulfonylated amidines formed as intermediates when the transhydrogenative C-N bond-forming reaction is carried out in air act as novel ligands to stabilize the catalyst.
- Shi, Feng,Tse, Man Kin,Cui, Xinjiang,Goerdes, Dirk,Michalik, Dirk,Thurow, Kerstin,Deng, Youquan,Beller, Matthias
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supporting information; experimental part
p. 5912 - 5915
(2009/12/08)
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- Copper-catalyzed N-alkylation of sulfonamides with benzylic alcohols: Catalysis and mechanistic studies
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The N-alkylation of sulfonamides with alcohols is efficiently performed in the presence of easily available copper catalysts via hydrogen borrowing methodology. Applying a copper acetate/potassium carbonate system the reaction of sulfonamides and alcohols gave the corresponding secondary amines in excellent yield. In situ HR-MS analysis indicated that bissulfonylated amines are formed under air atmosphere, which act as self-stabilizing Iigands for the catalytic system. UV-visible measurements suggest the interaction between the copper centre and the bissulfonylated amine. Reactions of benzyl alcohol-d 7 with p-toluenesulfonamide, Nbenzyl-p-toluenesulfonamide or N-benzylidenetoluenesulfonamide revealed that the reaction proceeds via a transfer hydrogenation mechanism and the whole process is micro-reversible. Competitive reactions of benzyl alcohol and benzyl alconol-d7 with ptoluenesulfonamide revealed a kinetic isotope effect (kH/kD) of 3.287 (0.192) for the dehydrogenation of benzyl alcohol and 0.611 (0.033) for the hydrogenation of the N-benzylidene-p-toluenesulfonamide intermediate, which suggests that dehydrogenation of the alcohol is the rate-determining step.
- Cui, Xinjiang,Shi, Feng,Tse, Man Kin,Goerdes, Dirk,Thurow, Kerstin,Beller, Matthias,Deng, Youquan
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scheme or table
p. 2949 - 2958
(2010/03/24)
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- Borrowing hydrogen methodology for the conversion of alcohols into N-protected primary amines and in situ deprotection
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Alcohols have been converted into a range of protected amines including sulfonamides and N-alkylbenzylamine derivatives. Representative examples of deprotection to afford primary amines are also provided.
- Lamb, Gareth W.,Watson, Andrew J.A.,Jolley, Katherine E.,Maxwell, Aoife C.,Williams, Jonathan M.J.
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experimental part
p. 3374 - 3377
(2009/09/05)
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- Preparation of bis(β-trimethylsilylethanesulfonyl)imide and its use in the synthesis of protected amine derivatives
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Bis(β-trimethylsilylethanesulfonyl)imide (SES2-NH) can be easily prepared in 85% yield by alkylation of the trianion of bismethanesulfonimide with 2 equiv of commerically available (iodomethyl)trimethylsilane. This synthon undergoes effective M
- Dastrup, David M.,VanBrunt, Michael P.,Weinreb, Steven M.
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p. 4112 - 4115
(2007/10/03)
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- β-TRIMETHYLSILYLETHANESULFONYL CHLORIDE (SES-Cl): A NEW REAGENT FOR PROTECTION OF AMINES
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The title compound, easily prepared in two steps from vinyltrimethylsilane, is a useful reagent for the protection of primary and secondary amines as their sulfonamides, which are cleaved by fluoride ion.
- Weinreb, Steven M.,Demko, Donald M.,Lessen, Thomas A.,Demers, James P.
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p. 2099 - 2102
(2007/10/02)
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