Fluorous Oxime Palladacycle: A Precatalyst for Carbon–Carbon Coupling Reactions in Aqueous and Organic Medium
作者:Woen Susanto、Chi-Yuan Chu、Wei Jie Ang、Tzyy-Chao Chou、Lee-Chiang Lo、Yulin Lam
DOI:10.1021/jo202482h
日期:2012.3.16
To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for a wide range of carbon carbon bond formation reactions (Suzuki-Miyaura, Sonogashira, Stille, Heck, Glaser-type, and Kumada) in either aqueous or organic medium under microwave irradiation. Palladacycle 1 could be recovered through F-SPE in various coupling reactions with recovery ranging from 84 to 95% for the first cycle. Inductively coupled plasma optical emission spectrometry (ICP-OES) analyses of the Pd content in the crude product from each class of transformation indicated extremely low levels of leaching and the palladacycle could be reused four to five times without significant loss of activity.
Arylation of Terminal Alkynes by Aryl Iodides Catalyzed by a Parts-per-Million Loading of Palladium Acetate
under mol ppm catalytic conditions. Reaction-rate analysis, transmission electron microscopic (TEM) examination of the reaction mixture, and mercury-amalgamation test were performed to gain insight into the activespecies of the highlyactive ppm catalyticspecies. TEM examination of the reaction mixture revealed that palladium nanoparticles were generated in situ under the reaction conditions, and
Synthesis of Fused 4-Iodoselenophene[2,3-<i>b</i>]thiophenes by Electrophilic Cyclization of 3-Alkynylthiophenes
作者:André L. Stein、Juliana da Rocha、Paulo Henrique Menezes、Gilson Zeni
DOI:10.1002/ejoc.200901118
日期:2010.2
We present here our results on the electrophilic cyclization reaction of 3-alkynylthiophenes with different electrophiles such as I 2 , ICl, and PhSeBr. The cyclization reaction proceeded cleanly under mild reaction conditions, giving fused 4-iodoselenophene[2,3-b]thiophenes in excellent yields. In addition, the obtained chalcogenophenes were readily transformed into more complex products through palladium-
我们在此展示了 3-炔基噻吩与不同亲电试剂(如 I 2 、ICl 和 PhSeBr)的亲电环化反应的结果。环化反应在温和的反应条件下顺利进行,以优异的产率得到稠合的 4-碘硒吩[2,3-b]噻吩。此外,通过钯或铜催化与硫醇、硼酸和有机锌试剂的交叉偶联反应,获得的硫属元素很容易转化为更复杂的产物。