Direct selective desaturation of carbonylcompounds to synthesize α,β-unsaturated carbonylcompounds represents an environmentally benign alternative to classical stepwise procedures. In this study, we designed an ideal CeO2-supported Pd(II)-on-Au nanoparticle catalyst (Pd/Au/CeO2) and successfully achieved heterogeneously catalyzed selective desaturation of cyclohexanones to cyclohexenones using O2
羰基化合物的直接选择性去饱和以合成α,β-不饱和羰基化合物代表了传统逐步方法的环保选择。在这项研究中,我们设计了一种理想的CeO 2负载的Au上Pd(II)纳米粒子催化剂(Pd / Au / CeO 2),并成功地使用空气中的O 2作为氧化剂,实现了环己酮向环己酮的非均相催化选择性脱饱和。除环己酮外,还可以在露天条件下,在Pd / Au / CeO 2存在下,由相应的饱和酮合成各种生物活性烯酮。初步的机理研究表明,底物中的α-C–H键断裂是该去饱和反应的营业额限制步骤。
Diels-Alder reactions of (trifluoromethyl)ethene and (trifluoromethyl)styrenes with functionalized butadienes
作者:Iwao Ojima、Momoko Yatabe、Takamasa Fuchikami
DOI:10.1021/jo00132a015
日期:1982.5
Experimental Studies on the Selective β-C–H Halogenation of Enones
Here we describe the realization of a one-pot protocol for the β-C–H halogenation of cyclic enones via umpolung of the β-carbon. The developed method includes hydrazone formation and selective β-halogenation (bromination, chlorination) with N-bromosuccinimide and Palau’chlor (2-chloro-1,3-bis(methoxycarbonyl)guanidine) followed by hydrolysis of the hydrazone moiety. Using the optimized conditions,
Synthesis of Cyclic Enones via Direct Palladium-Catalyzed Aerobic Dehydrogenation of Ketones
作者:Tianning Diao、Shannon S. Stahl
DOI:10.1021/ja206575j
日期:2011.9.21
carbonyl compounds are versatile intermediates in the synthesis of pharmaceuticals and biologically active compounds. Here, we report the discovery and application of Pd(DMSO)(2)(TFA)(2) as a catalyst for direct dehydrogenation of cyclohexanones and other cyclicketones to the corresponding enones, using O(2) as the oxidant. The substrate scope includes heterocyclic ketones and several natural-product