第一个利用酰亚胺自由基的催化策略已经开发出来。这种方法可以通过光催化还原烯丙醇的肟酰亚胺酯来实现烯丙醇的烯烃双官能化。随后的亚氨酸酯自由基经历连续的分子内和分子间反应,通过三种不同的自由基机制提供(i)氢胺化、(ii)氨基烷基化或(iii)氨基芳基化。介绍了这种亚胺酯自由基反应催化方法的广泛范围和实用性,以及与其他 N 中心自由基和互补的闭壳亚胺酯途径的比较。
第一个利用酰亚胺自由基的催化策略已经开发出来。这种方法可以通过光催化还原烯丙醇的肟酰亚胺酯来实现烯丙醇的烯烃双官能化。随后的亚氨酸酯自由基经历连续的分子内和分子间反应,通过三种不同的自由基机制提供(i)氢胺化、(ii)氨基烷基化或(iii)氨基芳基化。介绍了这种亚胺酯自由基反应催化方法的广泛范围和实用性,以及与其他 N 中心自由基和互补的闭壳亚胺酯途径的比较。
Mechanisms of Acid-Catalyzed <i>Z</i>/<i>E</i> Isomerization of Imines
作者:James E. Johnson、Nora M. Morales、Andrea M. Gorczyca、Debra D. Dolliver、Michael A. McAllister
DOI:10.1021/jo010067k
日期:2001.11.1
The kinetics and mechanism of acid-catalyzed Z/E isomerization of O-methylbenzohydroximoyl chloride (1Za and 1Ea), methyl O-methylbenzohydroximate (1Zb and 1Eb), ethyl O-methylbenzohydroximate (1Zc and 1Ec and five para and meta substituted derivatives), O-methylcinnamohydroximoyl chloride (2Za and 2Ea), and methyl O-methylcinnamohydroximate (2Zb and 2Zb) have been investigated. The kinetics of Z/E
Mechanism of bimolecular substitution reactions of hydroximoyl halides with amines in actonitrile solution
作者:James E. Johnson、Susan M. Dutson、Debra D. Dolliver、Susan L. Todd、Martha Hotema
DOI:10.1002/poc.610080505
日期:1995.5
ρ-value (with σ) for the reaction with pyrrolidine is +0·92. The reaction of the p-nitro compound with pyrrolidine gives a significant element effect [k(p-nitrobenzohydroximoyl bromide)/k(p)-nitrobenzohydroximoyl chloride = 10]. A Brϕonsted β-value of 0·38 was estimated from the reactions of morpholine and piperidine with the p-nitrohydroximoyl chloride. The slower reaction of (E)-O-methyl-p-nitrobenzohydroximoyl
(Z)-O-甲基苯并氢氧氯化物[ArC(Cl)NOCH 3 ]在乙腈溶液中与吗啉,吡咯烷和氮杂环丁烷反应,得到相应的(Z)-氨基肟[ArC(NR 1 R 2)NOCH 3 ]在乙腈中的反应。这些反应的速率是在拟一级条件(过量胺)下测量的。发现反应遵循总体二级动力学(在胺中一级)。与吡咯烷反应的哈米特ρ值(带有σ)为+ 0·92。对硝基化合物与吡咯烷的反应产生了显着的元素效应[ k(p-硝基苯甲氧基肟基溴化物/ k(p)-硝基苯甲氧基肟基氯= 10]。从吗啉和哌啶与对-硝基羟肟基氯的反应估计布朗斯通的β值为0·38 。(E)-O-甲基-对硝基苯并氧肟基氯与氮杂环丁烷的较慢反应主要产生(E)-ami胺肟(E:Z≈98:2)此反应也遵循二级动力学。将该研究中的动力学观察结果与在苯溶液中早期工作中获得的相应结果进行比较。建议在乙腈溶液中,反应通过加成消除机理进行,该速率决定氯离子的损失速率(A N
Johnson, James Elver; Maia, Joanne A.; Tan, Karen, Journal of Heterocyclic Chemistry, 1986, vol. 23, p. 1861 - 1868
作者:Johnson, James Elver、Maia, Joanne A.、Tan, Karen、Ghafouripour, Abdolkarim、de Meester, Patrice、Chu, Shirley S. C.
DOI:——
日期:——
Rates of acid-catalyzed geometric isomerization of some compounds containing a carbon-nitrogen double bond
The imino 1,2-Wittig rearrangement of hydroximates provides a novel method for the construction of 2-hydroxyoxime ethers. Upon treatment with LDA, Z-hydroximates smoothly underwent stereoselective rearrangement to give Z-2-hydroxyoxime ethers in good yield, which were converted into amino alcohols. On the other hand, the rearrangement of E-hydroximates gave a mixture of E- and Z-2-hydroxyoxime ethers. This method was successfully applied to a practical synthesis of cytoxazone. (C) 2004 Elsevier Ltd. All rights reserved.