A NEW METHOD FOR MIXED HALOGENATION. N-CHLOROAMINE-PHOSPHORUS BROMIDE SYSTEM AS A SYNTHETIC EQUIVALENT OF THE MIXED HALOGEN Cl+Br−
摘要:
A new method for the mixed halogenation of alkenes has been proposed based on the reaction of olefins with N-chloroamines in the presence of phosphorus bromide or oxybromide. The plausible reaction mechanism and the results of reactions with a number of model unsaturated compounds such as cyclohexene, 1-heptene. ethyl cinnamate, norbornene and those from the bicyclo[2.2.1]heptane series are discussed. In the reactions with reactive olefins this reagent acts as a synthetic equivalent of the unknown mixed halogen [Cl+Br-] with "abnormal" polarity of halogen atoms. The same reactions activated by PCl3 or POCl3 result in dichlorides in yields near to quantitative.
Practical and regioselective amination of arenes using alkyl amines
作者:Alessandro Ruffoni、Fabio Juliá、Thomas D. Svejstrup、Alastair J. McMillan、James J. Douglas、Daniele Leonori
DOI:10.1038/s41557-019-0254-5
日期:2019.5
these molecules are assembled through the stepwise introduction of a reactivity handle in place of an aromatic C-H bond (that is, a nitro group, halogen or boronic acid) and a subsequent functionalization or cross-coupling. Here we show that aromaticamines can be constructed by direct reaction of arenes and alkyl amines using photocatalysis, without the need for pre-functionalization. The process
Vacuum Gas/Solid<i>N</i>-Chlorination: Preparative Scale Synthesis of Volatile<i>N</i>-Chloramines
作者:J. C. Guillemin、J. M. Denis
DOI:10.1055/s-1985-31450
日期:——
A simple method for the preparative scale synthesis of volatile chloramines free from impurities starting from the corresponding primary or secondary amine using N-chlorosuccinimide as chlorinating agent is described.
The oxidation of aliphaticamines by aqueous chlorine has been studied. The kinetic behaviour is similar for primary, secondary and tertiary aliphaticamines, the elementary step being the transfer of chlorine from the hypochlorous acid molecule to the nitrogen of the free amino group. Chlorination of aliphatic primary and secondary amines involves some water molecules in the transition state. Inductive
Kinetics and Mechanism of Chlorine Exchange between Chloramine‐T and Secondary Amines
作者:Hana Dannan、Peter A. Crooks、Lewis W. Dittert、Anwar Hussain
DOI:10.1002/jps.2600810712
日期:1992.7
kinetics and mechanisms of chlorine transfer from chloramine-T (CAT) to several amines are second order and independent of p-toluenesulfonamide concentration; thus, the reaction does not involve disproportionation of CAT to dichloramine-T. From the profile of pH versus rate, the following mechanisms were proposed: (1) reaction of the ionized species of CAT with the ionized amine (ionic mechanism) and (2)
氯从氯胺-T(CAT)转移到几种胺的动力学和机理是二阶的,与对甲苯磺酰胺的浓度无关。因此,该反应不涉及CAT向二氯胺-T的歧化。根据pH与速率的关系曲线,提出了以下机理:(1)CAT的离子化种类与电离胺的反应(离子机理)和(2)CAT的非离子化种类与未电离的反应胺(非离子机理)。计算的离子和非离子机理的二阶,pH无关速率常数分别为1.6和5 x 10(6)M-1 s-1。尽管这两种机制在动力学上是无法区分的,非离子机理的速率常数与针对涉及不可离子化的氯胺(例如N-氯琥珀酰亚胺,N-氯喹核苷和N-氯-N-甲基苯磺酰胺)的类似氯化反应计算的速率常数处于相同数量级。提出的氯交换机理涉及处于环状六元过渡态的水分子。
Copper-catalyzed one-pot oxidative amidation between methylarenes and amines
A new method for the direct one-pot oxidative amidation between methylarenes and amines catalyzed by copper has been developed. This method integrates methylarene oxidation and amide bond formation, which are usually accomplished separately, into a single operation. In addition, the reaction provides a relatively high yield and has a wide substrate scope. Moreover, the starting reagents are abundant