Palladium-Catalyzed [5 + 1] Annulation of Salicylic Acid Derivatives and Propargylic Carbonates
作者:Kazuya Sato、Yohei Ogiwara、Norio Sakai
DOI:10.1246/bcsj.20200199
日期:2020.12.15
A palladium-catalyzed annulation reaction between salicylicacid derivatives and propargylic carbonates via the cleavage of a propargylic carbon–oxygen bond is described. This rare annulation react...
Axial-to-Central Chirality Transfer for Construction of Quaternary Stereocenters via Dearomatization of BINOLs
作者:Xiao-Long Min、Xu-Ran Xu、Ying He
DOI:10.1021/acs.orglett.9b03558
日期:2019.11.15
All-carbonquaternary stereocenters are versatile building blocks, and their asymmetric construction has attracted much attention. Herein, we disclose an axial-to-central chirality transfer strategy for the synthesis of chiralquaternary stereocenters via dearomatization of (S)-BINOLs. The reaction proceeded smoothly with a wide range of propargyl carbonates to afford chiral spiro-compounds in high
Copper(I) bromide-promoted reactions of bromo[(diethoxyphosphoryl)difluoromethyl]zinc reagent 2 with propargylic tosylates and acetates were examined. The reaction proceeded in an SN2′ manner to give allenic (α,α-difluoromethylene)phosphonates in good to excellent yield.
A palladium-catalyzed multicomponent reaction (MCR) of propargylic carbonates with isocyanides is reported. Remarkably, the orderly insertion of isocyanides affords two types of valuable N-heterocyclic products (Z)-6-imino-4,6-dihydro-1H-furo[3,4-b]pyrrol-2-amines and (E)-5-iminopyrrolones in high yields. Systematic analysis of the reaction conditions indicates that the selectivity of these N-heterocyclic
报道了炔丙基碳酸酯与异氰酸酯的钯催化的多组分反应(MCR)。值得注意的是,有序插入异氰酸酯可提供两种有价值的N-杂环产物(Z)-6-亚氨基-4,6-二氢-1 H-呋喃[3,4- b ]吡咯-2-胺和(E) -5-亚氨基吡咯烷酮产量高。反应条件的系统分析表明,这些N-杂环产物的选择性可以通过配体和温度控制。
作者:Changwei Shao、Xinyan Wang、Qun Zhang、Sheng Luo、Jichen Zhao、Yuefei Hu
DOI:10.1021/jo200869a
日期:2011.8.19
In this novel acid–base jointly promoted CuAAC, the combination of CuI/DIPEA/HOAc was developed as a highly efficient catalytic system. The functions of DIPEA and HOAc have been assigned, and HOAc was recognized to accelerate the conversions of the C–Cu bond-containing intermediates and buffer the basicity of DIPEA. As a result, all drawbacks occurring in the popular catalytic system CuI/NR3 were overcome
在这种新型的酸碱共同促进的CuAAC中,CuI / DIPEA / HOAc的结合被开发为一种高效的催化体系。已经指定了DIPEA和HOAc的功能,HOAc被认为可以加速含C–Cu键的中间体的转化并缓冲DIPEA的碱性。结果,容易克服了流行的催化体系CuI / NR 3中发生的所有缺点。