Lithium-<i>N</i>-lithioalkyldithiocarbamate: Neue<i>N</i>-Alkylaminoalkylanion-Äquivalente IV<sup>1</sup>; Eine neue Methode zur Darstellung 2-substituierter Indoline
作者:Hubertus Ahlbrecht、Christine Schmitt
DOI:10.1055/s-1994-25619
日期:——
Lithium N-Lithioalkyldithiocarbamates: New N-Alkylaminoalkyl Anion Equivalents IV1; A New Method for the Preparation of 2-Substituted Indoline Derivatives Metalation of the 2-position in indolines is feasible via the dithio-carbamate derivative using s-butyllithium. In a one-pot procedure, treatment with alkyl halides, carbonyl compounds, oxiranes and imines leads to the corresponding 2-substituted indoline derivatives.
Mixed carboxylic–sulfonic anhydride in reaction with imines: a straightforward route to water-soluble β-lactams <i>via</i> a Staudinger-type reaction
作者:Olga Bakulina、Dmitry Dar'in、Mikhail Krasavin
DOI:10.1039/c8ob00768c
日期:——
carboxylic–sulfonic anhydride in reaction with imines is reported. Unlike its well-studied isostere homophthalic anhydride, benzo[c][1,2]oxathiin-3(4H)-one 1,1-dioxide gave no product of a formal [4 + 2] cycloaddition and only followed an alternative reaction pathway toward β-lactams, presumably, via a formal [2 + 2] cycloaddition (a Staudinger-type reaction). Optimized reaction conditions involve the use
据报道,第一个使用混合的羧酸-磺酸酐与亚胺反应的例子。与苯丙[ c ] [1,2]恶臭素-3(4 H)-1,1,1-二氧化物不同,它的研究方法广为人知,它没有形成正式的[4 + 2]环加成反应的产物,并且仅在可替代的反应后进行可能通过正式的[2 + 2]环加成反应(Staudinger型反应)通向β-内酰胺的途径。优化的反应条件包括使用三乙胺作为碱助催化剂,这还允许通过常规柱色谱法分离相应的三乙铵盐形式的产物β-内酰胺苯磺酸。反应显示出对反式有一些偏爱-异构体形成;在某些情况下,可以分离出纯的非对映异构体。
Unusually Reactive Cyclic Anhydride Expands the Scope of the Castagnoli–Cushman Reaction
“azole-including” cyclic anhydrides in the Castagnoli–Cushman reaction with imines, a remarkably reactive, pyrrole-based anhydride has been identified. It displayed a remarkably efficient reaction with N-alkyl and N-aryl imines, in particular, with “enolizable” α-C-H imines which typically fail to react with a majority of known cyclic anhydrides. The reactivity of this anhydride has been justified by
of heterocyclic product space accessible by the Castagnoli–Cushman reaction (CCR) has been achieved via the use of glutaric anhydride analogues containing endocyclic substitutions with oxygen, nitrogen, and sulfur. Incorporation of these heteroatoms in the anhydride’s backbone results in enhanced reactivity and generally lower temperatures that are required for the reactions to go to completion. These