One-step synthesis of substituted isobenzofuran-1(3H)-ones and isobenzofuran-1,3-diones from indane derivatives in subcritical media
摘要:
Molecular oxygen is one of the most attractive oxidants in organic synthesis because it is highly soluble in subcritical water. In this study, indane derivatives were oxidized to the corresponding isobenzofuran-1(3H)-one with molecular oxygen and isobenzofuran-1,3-dione with a mixture of molecular oxygen and H2O2 in subcritical water. This paper describes a simple, economic, environmentally benign,and general procedure that can be used for the synthesis of substituted isobenzofuran-1(3H)-ones and isobenzofuran-1,3-diones in only one step and without catalyst.
Halogenation of ketones with N-halosuccinimides under solvent-free reaction conditions
作者:Igor Pravst、Marko Zupan、Stojan Stavber
DOI:10.1016/j.tet.2008.03.048
日期:2008.5
Several aryl substituted ketones, cyclic ketones, 1,3-diketones and a β-ketoamide were halogenated with N-halosuccinimides under solvent-free reaction conditions (SFRC) at various temperatures (20–80 °C), whereas less enolized ketones required the presence of an acid catalyst (p-toluenesulfonic acid, PTSA). Bromination of substituted acetophenones obeys first order kinetics v=kBr[ketone] and the following
在无溶剂反应条件下(SFRC),在各种温度(20-80°C)下,将N-卤代琥珀酰亚胺卤代数个芳基取代的酮,环酮,1,3-二酮和β-酮酰胺,而较少烯醇化的酮则需要存在酸催化剂(对甲苯磺酸,PTSA)。取代的苯乙酮的溴化反应遵循一级动力学v = k Br [酮],并与酮-烯醇平衡常数具有以下相关性:log k Br = 0.3p K E + C 1,少酚化的底物更具反应性;在速率确定步骤中产生的适度正电荷已通过Hammett相关性得到证实(ρ = -0.5)。另一方面,在环状酮中观察到相反的关系:log k Br = -0.6p K E + C 2,表明具有较高烯醇化常数(K E)的底物具有较高的反应性。发现在SFRC溴化之前,溶剂(MeCN,MeOH)的性质在酮-NBS-PTSA混合物的预组织中起着重要作用。
Thioglycoluril as a Novel Organocatalyst:
Rapid and Efficient α-Monobromination of 1,3-Dicarbonyl
Compounds
作者:Anxin Wu、Liping Cao、Jiaoyang Ding、Guodong Yin、Meng Gao、Yitao Li
DOI:10.1055/s-0029-1216746
日期:——
Thioglycoluril as a novel hydrogen-bonding organocata- lyst, combined with NBS, in MeOH provided rapid and efficient α-monobromination of 1,3-dicarbonylcompounds in excellent yields at room temperature. A bifunctional catalytic mechanism was proposed from these results.
Directed regioselectivity of bromination of ketones with NBS: solvent-free conditions versus water
作者:Igor Pravst、Marko Zupan、Stojan Stavber
DOI:10.1016/j.tetlet.2006.04.119
日期:2006.7
The reaction conditions employed directed the site of functionalisation of ketones with NBS: under solvent-free conditions α-bromination was the exclusive process, while in water, ring functionalisation occurred in the case of methoxy substituted aromatic ketones.
3-(Trifluoromethyl)indenyl Cation: Ion Pair Return in the Formation of an Antiaromatic and Electron-Deficient Doubly Destabilized Carbocation
作者:Annette D. Allen、Mizue Fujio、Nageib Mohammed、Thomas T. Tidwell、Yutaka Tsuji
DOI:10.1021/jo961387k
日期:1997.1.1
measuring the dependence of the reactivity of 15 on the solvent-ionizing parameter Y(OTs) is 0.78, which is significantly less than that of 1.23 for the analogous 9-(trifluoromethyl)-9-fluorenyl tosylate 7. Normal salt effects in CF(3)CO(2)H predominate for 15, and the special salt effect involves no more than 14% capture of solvent-separated ion pairs by 0.551 M KO(2)CCF(3). The substrate 15 has a
3-(三氟甲基)-3-茚基甲苯磺酸酯(15)的溶剂分解发生广泛异构化成1-(三氟甲基)-3-茚基甲苯磺酸酯(16),后者在较慢的过程中反应生成取代产物17。动力学分析涉及中间烯丙基阳离子/甲苯磺酸根离子对18的模型的结果表明,CD(3)CO(2)D在99.6摄氏度下18的分配比为7.7,与溶剂捕获相比,通过烯丙基重排返回。具有特定(18)O标记的15的研究表明,在回收的15中没有加扰,在重新排列为16时也没有部分加扰。测量15的反应性对溶剂电离参数Y(OTs)的依赖性的m值为0.78,这是对于9-(三氟甲基)-9-芴基甲苯磺酸酯7而言,其显着小于1.23的水平。在CF(3)CO(2)H中,正常的盐效应在15中占主导地位 特殊的盐效应涉及0.551 M KO(2)CCF(3)捕获不超过14%的溶剂分离离子对。相对于仲茚基甲苯磺酸酯22,衬底15的反应性净减少大于10(9),其中10(6)和1