62084-35-9Relevant articles and documents
Reaction Route and Mechanism of the Direct N-Alkylation of Sulfonamides on Acidic Mesoporous Zeolite β-Catalyst
Fu, Wenqian,Shen, Runsheng,Bai, Enhui,Zhang, Lei,Chen, Qun,Fang, Zhongxue,Li, Guangchao,Yi, Xianfeng,Zheng, Anmin,Tang, Tiandi
, p. 9043 - 9055 (2018/09/11)
Development of highly active heterogeneous catalysts with strong acidity and mesoporous structure is a highly attractive strategy for organic synthesis. In this study, a mesoporous zeolite beta (HBeta-M) with bulky particle size and strong acidity was synthesized and used in the direct N-alkylation of sulfonamides with alcohols. The strongly acidic HBeta-M had a higher intrinsic activity with initial turnover frequency of 11 × 10-2 s-1 than those of H-form mordenite nanosheets (3.3 × 10-2 s-1) and montmorillonite (4.0 × 10-2 s-1) catalysts. The experiment and characterization results demonstrate that there are two parallel reaction routes on the acidic catalysts. One route is the reaction of benzhydrol with p-toluenesulfonamide (route I). Another route is the reaction of dibenzhydryl ether, arising from route I, with p-toluenesulfonamide (route II), which is found in this work. The reaction rate of route I (13 × 10-3 mol kg-1 s-1) was higher than that of route II (9.8 × 10-3 mol kg-1 s-1) on HBeta-M, but route II predominantly contributed to the formation of the target product with high selectivity. Hereby, a complete reaction mechanism is proposed in this work.
Sulfonic acid-functionalized ionic liquids as metal-free, efficient and reusable catalysts for direct amination of alcohols
Han, Feng,Yang, Lei,Li, Zhen,Xia, Chungu
experimental part, p. 1052 - 1060 (2012/05/21)
A series of sulfonic acid-functionalized (SO3H-functionalized) ionic liquids was synthesized and used as metal-free, highly selective and efficient catalysts for the direct amination of alcohols. Notably, the activities of the series of SO3H-functionalized ionic liquids were compared and a 92% isolated yield was obtained using 3-tetradecyl-1-(butyl-4- sulfonyl)imidazolium trifluoromethanesulfonate ([BsTdIM][OTf]) as the catalyst. Importantly, the catalytic system has wide substrate scope including benzylic, allyl, propargylic, aliphatic alcohols with sulfonamide, amide, carbamate, aromatic amine and N-heterocyclic compounds. Interestingly, the system was also suitable for a multi-gram scale direct amination of alcohols. Additionally, the reusable nature of [BsTdIM][OTf] makes this protocol more attractive and avoids the disposal and neutralization of acidic catalysts. Moreover, preliminary experiments indicated that this reaction should proceed via an SN1 pathway. Copyright
Evidence for rate limiting C-H bond cleavage in the leuckart reaction
Awachie, Peter I.,Agwada, Vincent C.
, p. 1899 - 1910 (2007/10/02)
A rho value of +0.21 is reported for the reaction of mono 4-substi- tuted benzophenones with formamide. This, in conjunction with a kinetic iso- tope effect value of 1.80 obtained for the system, suggests a rate-limiting C-H bond cleavage.
