Manganese Dioxide Catalyzed N-Alkylation of Sulfonamides and Amines with Alcohols under Air

Abstract

By simply running the reactions under air and solvent-free conditions using catalytic amounts of manganese dioxide, a practical and efficient N-alkylation method for a variety of sulfonamides and amines using alcohols as green alkylating reagents was developed.

Heterostructured Hybrid rGO@α‐MnO2/rGO@δ‐MnO2 Nanoflower: An Efficient Catalyst for Aerobic Solvent‐Free N‐Alkylation Reactions and Energy Storage Material

“…As shown in Table , the yield of the desired product increased (80 %) with the increment in catalyst loading (20 wt%) in the presence of 0.3 mmol of KOH (entry 12). The highest yield (98 %) of desired product was found when the reaction was carried out in the presence of 10 wt% of catalyst and 0.6 mmol of KOH at 100 °C within 10 h, shortest time in comparison with the other reported literatures (Table , entry 13) . The product yield was reduced to 90 %, when rGO@α‐MnO 2 /rGO@δ‐MnO 2 , annealed at 450 °C, was used as the catalyst (10 wt% and 0.6 mmol of KOH) in the reaction medium (Table , entry 14).…”

“…It not only generates unpaired electrons during the self or auto hydrogen transfer process, but also these species need to be transferred to the intermediate too. These reactions were performed in the presence of small amount of catalyst at 100 °C and produced high yield of the desired products, with a maximum up to 98 % within 10 h along with negligible leaching problem, which appeared as much better results, in comparison to the other reported procedures . In addition, such efficient unpaired electron transferring heterogeneous nanocatalyst proved to be a promising energy storage material.…”

“…But, the method needs to be improved as these reactions demand costly metal complexes and requires inert atmosphere along with special equipment including glove box. Moreover, Xu and co‐workers carried out MnO 2 ‐catalyzed N ‐alkylation of amines with alcohols under air, which is relevant to the present work . But, the method suffered from very high temperature (135 °C), very long time (24 h to 35 h), and only moderate to good yield.…”

Recent Advances of Transition Metal-Catalyzed Aerobic Dehydrative Reactions of Alcohols and Amines and Related Researches

“…2011 年, Tang 和 Cheng [47] 报道了 [21,22,26,33,39] , 他们发现空 气同样对该 C-烷基化反应起到促进作用. 其次, 在醛 4 与酮 7 的羟醛缩合生成 α,β-不饱和酮 10 的一步, 他们发 现 Cu 催化剂同样可以大大促进反应进行(Eq.…”

General Reductive Amination of Aldehydes and Ketones with Amines and Nitroaromatics under H2 by Recyclable Iridium Catalysts

“…Thus, it is highly desirable to develop efficient and recyclable heterogeneous catalysts for the reductive amination of aldehydes or ketones with nitroaromatics and amines. Some heterogeneous catalysts, such as Pd, [10] Pt, [11] Ru, [12] Ir [13] and Mn [14] catalysts, were reported for the reductive amination of aldehydes and ketones, but the generality was not good. For example, the reductive amination of ketones is difficult, and the efficiency was not high enough using these catalysts.…”