Development of the Suzuki−Miyaura Cross-Coupling Reaction: Use of Air-Stable Potassium Alkynyltrifluoroborates in Aryl Alkynylations
作者:Gary A. Molander、Bryson W. Katona、Fouzia Machrouhi
DOI:10.1021/jo0262356
日期:2002.11.1
cross-coupling reaction of potassiumalkynyltrifluoroborates with aryl halides or triflates proceeds readily with moderate to excellent yields. The potassiumalkynyltrifluoroborates are air- and moisture-stable crystalline solids that can be stored indefinitely, which will provide an advantage in applications to combinatorial chemistry. The alkynyl cross-coupling reaction can be effected using 9 mol % of PdCl2(dppf)
Dynamic multiligand catalysis: A polar to radical crossover strategy expands alkyne carboboration to unactivated secondary alkyl halides
作者:Shin-Ho Kim-Lee、Pablo Mauleón、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1016/j.chempr.2021.06.002
日期:2021.8
triggers cooperative polar/radical pathways in a single catalytic cycle. This strategy has been applied to address a restricting limitation inherent to Cu-catalyzed B2pin2-carboboration of alkynes—the very low reactivity of the intermediate vinyl-Cu(I) species, which renders conventional methods ineffective with alkyl electrophiles other than simple primary halides. The crossover strategy enabled by
我们描述了基于前所未有的动态多配体配位池的 Cu 催化的双重策略,该池在单个催化循环中触发合作的极性/自由基途径。该策略已被应用于解决 Cu 催化的 B 2 pin 2固有的限制性限制-炔烃的碳硼化——中间体乙烯基-Cu(I) 物质的反应性非常低,这使得传统方法对烷基亲电试剂无效,而不是简单的伯卤化物。通过有机金属中间体中的配体交换实现的交叉策略克服了这一反应性问题,将碳硼化的范围扩大到未活化的仲烷基卤化物,并开辟了获得立体定义的四取代乙烯基硼酸酯的新途径。该方法具有区域选择性和立体选择性,显示出优异的官能团耐受性,并允许在任一反应伙伴处掺入复杂的碳环和杂环片段。
Copper-Catalyzed Aerobic Oxidative Transformation of Ketone-Derived<i>N</i>-Tosyl Hydrazones: An Entry to Alkynes
A novel strategy involving Cu‐catalyzedoxidative transformation of ketone‐derived hydrazone moiety to various synthetic valuable internal alkynes and diynes has been developed. This method features inexpensive metal catalyst, green oxidant, good functional group tolerance, high regioselectivity and readily available starting materials. Oxidative deprotonation reactions were carried out to form internal
Synthesis and characterization of novel chiral NHC–palladium complexes and their application in copper-free Sonogashira reactions
作者:Longguang Yang、Pei Guan、Pan He、Qian Chen、Changsheng Cao、Yu Peng、Zhan Shi、Guangsheng Pang、Yanhui Shi
DOI:10.1039/c2dt12391f
日期:——
A new series of chiral N-heterocyclic carbene (NHC) palladium complexes were synthesized from a relatively inexpensive amino acid, L-phenylalanine. All these compounds were fully characterized by 1H-NMR, 13C-NMR and elemental analysis. The X-ray molecular structures of two of the complexes were reported. The catalytic activity of the four palladium complexes was successfully tested in the Sonogashira reaction under copper free conditions in air. The palladium complex 3a provided good activity in the Sonogashira coupling reaction.
Electrochemically driven, Cp*Ir(III)-catalyzed regioselective annulative couplings of benzoicacids with alkynes have been established herein. The combination of iridium catalyst and electricity not only circumvents the need for stoichiometric amount of chemical oxidant, but also ensures broad reaction compatibility with a wide array of sterically and electronically diverse substrates. This electrochemical