铜(I)催化剂可通过使用合适的有机碱将二氧化碳插入炔烃的C H键中,利用该有机碱在热力学上可实现对羧酸盐的氢化以及碱的再生。在催化氯化铜(I)/ 4,7-二苯基-1,10-菲咯啉,聚合物结合的三苯基膦和2,2,6,6-四甲基哌啶为碱的情况下,末端炔烃在15 bar CO下进行羧化反应2,室温。过滤后,可以在铑/钼催化剂下将炔羧酸铵氢化为伯醇和水,以再生胺碱。这证明了无盐整体工艺的可行性,在该工艺中,二氧化碳可充当CH功能中C1的基石。
Palladium‐Catalyzed Regio‐ and Stereoselective Sulfonylation of Aryl Propiolates with Sulfonyl Hydrazides: Access to (
<i>E</i>
)‐
<i>β</i>
‐Aryl Sulfonyl Acrylates
An efficient method for the synthesis of (E)‐β‐arylsulfonylacrylates has been reported. This palladium‐catalyzed approach showed excellent regio‐ and stereoselectivity in the sulfonylation of arylpropiolates with sulfonylhydrazides. Through this approach, a wide range of (E)‐β‐arylsulfonylacrylates were obtained in moderate to high yields.
Palladium-Catalyzed Multicomponent Synthesis of Fully Substituted Alkylidene Furanones
作者:Ángel Rentería-Gómez、Rubén O. Torres-Ochoa、Rocío Gámez-Montaño、Qian Wang、Jieping Zhu
DOI:10.1021/acs.orglett.0c02578
日期:2020.9.4
In the presence of a catalytic amount of Pd(OAc)2 and XantPhos, the three-component reaction of ynones, imines, and aryl iodides affords fully substituted alkylidene-furan-3(2H)-ones via a sequence of the Mannich reaction followed by chemo- and regioselective oxypalladation and reductive elimination. One carbon–oxygen and two carbon–carbon bonds are generated to afford the heterocycle in good to excellent
Metal-free catalytic cascade to chromones: direct coupling of salicylaldehydes and activated alkynes triggered by aryloxyl radicals
作者:Ping Wang、Zhongfeng Li、Shengli Cao、Honghua Rao
DOI:10.1039/c5ra24634b
日期:——
The first intermolecular addition reaction of aryloxylradicals to CC bonds was disclosed, which can afford biologically important chromone scaffolds via a PhNMe3I-catalyzed direct coupling of readily available salicylaldehydes and activated internal alkynes in only one step, and can tolerate a range of catalytically reactive functional groups.
Carboxylic Acid Salts as Dual‐Function Reagents for Carboxylation and Carbon Isotope Labeling
作者:Shuo Wang、Igor Larrosa、Hideki Yorimitsu、Gregory J. P. Perry
DOI:10.1002/anie.202218371
日期:2023.3.27
The potassium salt of triphenylacetic acid is developed as a combined source of CO2 and base/metalating agent. This method avoids specialized equipment and is used in the carboxylation of a range of compound classes. This provides a mechanistically distinct approach to carboxylation that has also been applied in carbon isotopelabeling.
三苯乙酸的钾盐被开发为 CO 2和碱/金属化剂的组合来源。该方法无需专用设备,可用于一系列化合物类别的羧化。这提供了一种机械上不同的羧化方法,该方法也已应用于碳同位素标记。