在5 bar H 2下,使用RuPHOX-Ru作为手性催化剂,对各种α-取代的丙烯酸进行不对称氢化,从而以高达99%的收率和99.9%ee的产率提供相应的手性α-取代的丙酸。该反应可以以克级进行,具有相对较低的催化剂负载量(最高5000 S / C),所得产物(97%,99.3%ee)可用作构建生物活性手性分子的关键中间体。该不对称方案已成功应用于二氢青蒿酸的不对称合成,这是抗疟疾药物青蒿素工业合成所需的关键中间体。
在5 bar H 2下,使用RuPHOX-Ru作为手性催化剂,对各种α-取代的丙烯酸进行不对称氢化,从而以高达99%的收率和99.9%ee的产率提供相应的手性α-取代的丙酸。该反应可以以克级进行,具有相对较低的催化剂负载量(最高5000 S / C),所得产物(97%,99.3%ee)可用作构建生物活性手性分子的关键中间体。该不对称方案已成功应用于二氢青蒿酸的不对称合成,这是抗疟疾药物青蒿素工业合成所需的关键中间体。
Palladium-Catalyzed Tandem Reaction of Three Aryl Iodides Involving Triple C–H Activation
作者:Xiai Luo、Yankun Xu、Genhua Xiao、Wenjuan Liu、Cheng Qian、Guobo Deng、Jianxin Song、Yun Liang、Chunming Yang
DOI:10.1021/acs.orglett.8b00982
日期:2018.5.18
with two aryl iodides for the synthesis of spirooxindole has been achieved. The reaction underwent the process of triple C–Hactivation and four C–C bondformations based on the double trapping of transient spirocyclic palladacycles which are obtained through remote C–Hactivation.
functionality has been reliably transferred into nucleophilic radicals with the loss of one molecule of formaldehyde. Intriguingly, we found that the dehydroxymethylation process can be significantly promoted by the cerium catalyst, and the stabilization effect of the fragmented radicals also plays a significant role. This operationally simple protocol has enabled the direct utilization of primary alcohols as unconventional
Efficient Synthesis of Spirooxindole Pyrrolones by a Rhodium(III)‐Catalyzed C−H Activation/Carbene Insertion/Lossen Rearrangement Sequence
作者:Biao Ma、Peng Wu、Xing Wang、Zhengyu Wang、Hai‐Xia Lin、Hui‐Xiong Dai
DOI:10.1002/anie.201906589
日期:2019.9.16
A rhodium(III)-catalyzed domino annulation of simple olefins with diazo oxindoles to give spirooxindole pyrrolone products is described. This reaction can be formally viewed as the result of an anomalous tandem C-H activation, carbene insertion, Lossen rearrangement, and a nucleophilic addition process. The potential utility of this reaction was further demonstrated by the late-stage diversification
dialkoxycarbonylation of various aromatic and aliphatic alkynes affording a wide range of 1,4-dicarboxylic acid diesters in high yields and selectivities. Kinetic studies suggest the generation of 1,4-dicarboxylic acid diesters via cascade hydroesterification of the corresponding alkynes. Based on these investigations, the chemo- and regioselectivities of alkyne carbonylations can be controlled as shown by switching
A carboxyl-assisted C–H functionalization of acrylic acids with formaldehyde to give butenolides is described. It is the first time that the addition of an inert vinylic C–H bond to formaldehyde has been achieved via cobalt-catalyzed C–H activation. The unique reactivity of the cobalt species was observed when compared with related Rh or Ir catalysts. γ-Hydroxymethylated butenolides were produced by
描述了用甲醛对丙烯酸进行羧基辅助的 C-H 官能化以得到丁烯内酯。这是首次通过钴催化的 C-H 活化将惰性乙烯基 C-H 键添加到甲醛中。与相关的 Rh 或 Ir 催化剂相比,观察到钴物种的独特反应性。γ-羟甲基化丁烯内酯是通过Na 2 CO 3在一锅催化反应后处理制备的。