Conjugateaddition of α,β-unsaturated ketones with arylzinc species that form in situ from diethylzinc and a series of arylboronic acids by boron-zinc exchange reactions were investigated. 1,4-Addition products were formed in yields of 34-93%.
Stable and Reusable Palladium Nanoparticles-Catalyzed Conjugate Addition of Aryl Iodides to Enones: Route to Reductive Heck Products
作者:Naziya Parveen、Rajib Saha、Govindasamy Sekar
DOI:10.1002/adsc.201700823
日期:2017.11.10
efficient, binaphthyl‐backbone‐stabilized palladium nanoparticles (Pd‐BNP) catalyst for the 1,4‐addition of aryl halides to enones has been developed. The scope of the reaction has been studied with various substituted and sterically hindered aryl halides and enones to afford the conjugate additionproducts in good to excellent yields. The catalyst has been recovered and reused up to five times without
Superacid-Catalyzed Reactions of Cinnamic Acids and the Role of Superelectrophiles<sup>1</sup>
作者:Rendy、Yun Zhang、Aaron McElrea、Alma Gomez、Douglas A. Klumpp
DOI:10.1021/jo030327t
日期:2004.4.1
formation of dicationic intermediates (superelectrophiles), and the reactions can lead to either chalcone-type products or indanone products. The directobservation of a dicationic species (by low-temperature 13C NMR) is reported. We provide clear evidence that protonated carboxylic acid groups (or the corresponding acyl cation) can enhance the reactivity of an adjacent electrophilic center. Triflic acid
已经研究了肉桂酸和相关化合物的化学性质。在超酸催化的芳烃反应中,提出了两种相互竞争的反应机理。两种机理都涉及形成阳离子型中间体(超亲电子试剂),并且这些反应可导致查尔酮类产物或茚满酮产物。据报道直接观察到一种特殊的物质(通过低温13 C NMR)。我们提供了明确的证据,表明质子化的羧酸基团(或相应的酰基阳离子)可以增强相邻亲电中心的反应活性。三氟甲磺酸还被发现是从肉桂酸直接合成某些缺电子的查耳酮和杂环查耳酮的有效酸催化剂。
Decarboxylative substitution of β-keto acids to benzylic alcohols catalyzed by molecular iodine
作者:Fuzhong Han、Xinxin Zhang、Minggang Hu、Lina Jia
DOI:10.1039/c5ob01730k
日期:——
An efficient method for molecular iodine catalyzed decarboxylative substitution of β-keto acids with benzylic alcohols has been described.
一种高效的分子碘催化的β-酮酸与苄基醇脱羧取代反应的方法已被描述。
Arylboronic Acid Catalyzed Dehydrative Mono-/Dialkylation Reactions of β-Ketoacids and Alcohols
alcohols and β-ketoacids were realized under arylboronic acidcatalysis, furnishing a series of β-aryl ketones and β-ketoesters in yields of 15–99%, with CO2 and H2O being the byproducts. In this context, the decarboxylative alkylation reaction occurred to give β-aryl ketones at 50 °C, while the decarboxylation was suppressed to generate dialkylated ester products at 0 °C. A possible catalytic cycle was proposed