Thioamide and Thioester Cyclopentane Synthesis via Trimethyltin Radical Catalyzed Alkenylation of Substituted (Thiocarbonyl)cyclopropanes
摘要:
Thioamide cyclopropanes bearing phenyl substituents and thioamide- or thioester cyclopropanes bearing gem-dichloro and methyl substituents were subjected to trimethyltin radical catalyzed alkenylation to furnish the corresponding substituted (thiocarbonyl)cyclopentanes. The stereochemical outcome of these transformations can be rationalized by considering the effects of substituents, upon cyclization of the intermediate functionalized 5-hexenyl radicals.
A novel route to cyclopropyl ketones, aldehydes, and carboxylic acids.
作者:Karen E. Rodriques
DOI:10.1016/s0040-4039(00)79644-4
日期:1991.3
Cyclopropanation of α,β-unsaturated N-methoxy-N-methyl amides provided the cyclopropyl amides in far superior yields to those obtained with the corresponding ketones. The desired ketones are then readily accessible by the addition of organometallicreagents. Access to a variety functional groups, including aldehydes and carboxylic acids, is also described.
were successfully used in the Ni(CO)4 -induced carbonylation reactions of gem-dibromocyclopropanes. The nickel carbenoid and enolate complexes are considered to be involved as key intermediates. Protonation afforded the cyclopropanecarboxylic acid derivatives. The presence of an electrophile achieved another stereoselective carbon-carbon bond formation via the nickel enolate intermediate.
Potassium tert-Butoxide Facilitated Amination of Carboxylic Acids with N,N-Dimethylformamide
作者:Jing Zhang、Yuanjing Huang
DOI:10.1055/a-1817-1965
日期:2022.8
Herein a practical and efficient potassium tert-butoxide (KO t Bu)-facilitated amination of carboxylic acids with N,N-dimethylamine is described. In the presence of catalytic amount of KO t Bu, a variety of aliphatic and aromatic carboxylic acids are transformed to N,N-dimethylamides using DMF as the dimethylamine reagent with the assistance of trimethylacetic anhydride. The applicability of this protocol
本文描述了一种实用且有效的叔丁醇钾 (KO t Bu)-促进羧酸与N , N-二甲胺的胺化。在催化量的 KO t Bu 存在下,在三甲基乙酸酐的帮助下,使用 DMF 作为二甲胺试剂,多种脂肪族和芳香族羧酸转化为N,N-二甲基酰胺。该协议的适用性通过复杂药物分子的后期二甲基酰胺化得到证明。涉及 KO t的似是而非的反应机制 在机理研究的基础上,提出了由甲酰胺分解和酸酐介导的缩合促进 Bu 促进的原位胺生成。