在此,我们报道了一种配体控制的钯催化方法,该方法能够从同一组容易获得的芳基碘化物、芳基乙炔和 BrCF 2 CO 2 K 合成具有优异区域选择性的炔酮和 γ-丁烯内酯。在该反应中, [Pd II ]=CF 2确实表现出亲电性,与 H 2 O 反应时很容易生成 CO。与传统方法相比,它对环境友好且安全,并且当前的方案使我们能够以高产率提供炔酮和 γ-丁烯内酯出色的功能容差。此外,利用该策略还可以与相应的酚和醇获得酯。生物活性化合物后期功能化的成功进一步说明了该方案在材料开发和药物发现中的合成效用。
Iron‐Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3‐Diesters via a Functionalized Alkyl Radical
作者:Ming‐Qing Tian、Zhen‐Yao Shen、Xuefei Zhao、Patrick J. Walsh、Xu‐Hong Hu
DOI:10.1002/anie.202100641
日期:2021.4.19
Direct oxidative C(sp)−H/C(sp3)−H cross‐coupling offers an ideal and environmentally benign protocol for C(sp)−C(sp3) bond formations. As such, reactivity and site‐selectivity with respect to C(sp3)−H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron‐catalyzed/silver‐mediated tertiary alkylation of terminal alkynes with readily available and versatile 1
Heterolytic H<sub>2</sub> Cleavage and Catalytic Hydrogenation by an Iron Metallaboratrane
作者:Henry Fong、Marc-Etienne Moret、Yunho Lee、Jonas C. Peters
DOI:10.1021/om400281v
日期:2013.5.24
formal hydride transfer to the boron gives iron-borohydrido-hydride complexes. These compounds catalyze the hydrogenation of alkenes and alkynes to the respective alkanes. Notably, the boron is capable of acting as a shuttle for hydride transfer to substrates. The results are interesting in the context of heterolytic substrate addition across metal–boron bonds in metallaboratranes and related systems
H 2在铁硼烷中的铁-硼键上的可逆、异裂加成以及正式的氢化物转移到硼上得到铁-硼氢化物-氢化物复合物。这些化合物催化烯烃和炔烃氢化成相应的烷烃。值得注意的是,硼能够充当将氢化物转移到基材的穿梭机。在金属实验室和相关系统中跨金属-硼键的异溶底物添加以及金属-配体双功能催化的背景下,结果很有趣。
作者:Marcileia Zanatta、Francisco P. dos Santos、Cristina Biehl、Graciane Marin、Gunter Ebeling、Paulo A. Netz、Jairton Dupont
DOI:10.1021/acs.joc.6b03029
日期:2017.3.3
for the H/Dexchange reaction of various substrates using CDCl3 as D source, without the addition of any extra bases or metal. High deuterium incorporation (up to 49%) in acidic C–H bonds of ketone and alkyne substrates (pKa from 18.7 to 28.8) was found at room temperature. The reaction proceeds through the fast and reversible deuteration of the 2-methyl H of the imidazolium cation followed by D transfer
与碱性阴离子(例如碳酸氢盐,脯氨酸盐和咪唑酸盐)缔合的简单1,2,3-三烷基咪唑鎓阳离子是使用CDCl 3作为D源进行各种底物H / D交换反应的活性催化剂,而无需添加任何多余的碱或金属。酮和炔烃底物的酸性C–H键中氘的高掺入量(最高49%)(p K a在室温下发现(从18.7到28.8)。反应通过咪唑鎓阳离子的2-甲基H的快速可逆氘化进行,然后D转移至底物。IL充当中性碱催化剂,其中在反应过程中保持接触离子对。碱性活性位点归因于阴离子中存在一个偏远的碱性位点,即碳酸氢根的OH,脯氨酸根的NH和咪唑基阴离子中的活化水。详细的动力学实验表明,由于涉及溶剂对离子液体进行氘化的快速可逆反应,因此该反应在底物上相对于离子液体为一级伪零级。
Stereomutation in the Seyferth reaction
作者:Joseph B. Lambert、Eric G. Larson、Richard J. Bosch、Mollie L. E. TeVrucht
DOI:10.1021/ja00305a019
日期:1985.9
La reaction de cyclopropanation entre le dibromomethylene, obtenu a partir du reactif Seyferth (PhHgCBr 3 ), et les alcenes electroniquement deficients est non stereospecifique
La反应 de cyclopropanation entre le dibromomethylene, obtenu a partir du reactif Seyferth (PhHgCBr 3 ), et les alcenes electroniquement deficients est non立体特异性
Reaction of Alkynes and Azides: Not Triazoles Through Copper-Acetylides but Oxazoles Through Copper-Nitrene Intermediates
作者:Estela Haldón、Maria Besora、Israel Cano、Xacobe C. Cambeiro、Miquel A. Pericàs、Feliu Maseras、M. Carmen Nicasio、Pedro J. Pérez
DOI:10.1002/chem.201303737
日期:2014.3.17
Well‐defined copper(I) complexes of composition [Tpm*,BrCu(NCMe)]BF4 (Tpm*,Br=tris(3,5‐dimethyl‐4‐bromo‐pyrazolyl)methane) or [Tpa*Cu]PF6 (Tpa*=tris(3,5‐dimethyl‐pyrazolylmethyl)amine) catalyze the formation of 2,5‐disubstituted oxazoles from carbonyl azides and terminal alkynes in a direct manner. This process represents a novel procedure for the synthesis of this valuable heterocycle from readily