photocatalytic procedure that enables the acylation/arylation of unfunctionalized alkyl derivatives in flow. The method exploits the ability of the decatungstate anion to act as a hydrogen atom abstractor and produce nucleophilic carbon-centered radicals that are intercepted by a nickel catalyst to ultimately forge C(sp3)−C(sp2) bonds. Owing to the intensified conditions in flow, the reaction time can be reduced
Electrochemical 1,4-reduction of α,β-unsaturated ketones with methanol and ammonium chloride as hydrogen sources
作者:Binbin Huang、Yanan Li、Chao Yang、Wujiong Xia
DOI:10.1039/c9cc02368b
日期:——
sustainable, chemoselective 1,4-reduction of α,β-unsaturatedketones by means of an electrochemical method is presented, wherein the extremely inexpensive ammonium chloride (NH4Cl) is applied as the only additive. The reaction proceeds smoothly in the air at ambient temperature. Mechanistic studies reveal that both NH4Cl and solvent methanol work as hydrogen donors.
Nickel‐Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
作者:Jan Brauer、Elisabeth Quraishi、Lisa Marie Kammer、Till Opatz
DOI:10.1002/chem.202103486
日期:2021.12.23
Mediated synthesis: A strategy for the nickel-catalyzed synthesis of ketones using visible light and two carboxylic acid-derived substrates is presented. No expensive iridium catalysts are required, with eco-friendly Hantzsch ester acting as both the photosensitizer and photoreductant. A broad scope of synthesized ketones is presented along with spectroscopical and computational studies of the role
Visible-Light-Promoted Photocatalyst-Free Hydroacylation and Diacylation of Alkenes Tuned by NiCl<sub>2</sub>·DME
作者:Xinxin Zhao、Bing Li、Wujiong Xia
DOI:10.1021/acs.orglett.9b04595
日期:2020.2.7
4-dihydropyridines via an acyl radical addition and hydrogen atom transfer pathway under photocatalyst-free conditions. The efficiency was highlighted by wide substrate scope, good to high yields, successful scale-up experiments, and expedient preparation of highly functionalized ketone derivatives. In addition, this protocol allows for the synthesis of 1,4-dicarbonyl compounds through alkene diacylation in the presence
Hydrogen borrowing catalysis using 1° and 2° alcohols: Investigation and scope leading to α and β branched products
作者:James R. Frost、Choon Boon Cheong、Wasim M. Akhtar、Dimitri F.J. Caputo、Kirsten E. Christensen、Neil G. Stevenson、Timothy J. Donohoe
DOI:10.1016/j.tet.2021.132051
日期:2021.4
variety of ketonesusing 1° or 2° alcohols under hydrogen borrowing catalysis is described. Initial research focused on the α-alkylation of cyclopropyl ketones with higher 1° alcohols (i.e. larger than MeOH), leading to the formation of α-branchedproducts. Our search for additional substrates with which to explore this chemistry led us to discover that di-ortho-substituted aryl ketones were also privileged
描述了在氢借位催化下使用1°或2°醇对各种酮进行的烷基化。最初的研究集中在环丙酮与更高的1°醇(即大于MeOH)的α-烷基化反应上,导致形成α-支化产物。我们通过寻找其他底物来探索这种化学反应,使我们发现,二邻位取代的芳基酮也是特有的支架,其中Ph ∗(C 6 Me 5)酮是最佳选择。进一步的研究表明,该基序对于与2°醇形成β支链产物的烷基化至关重要,这也为研究非对映选择性和分子内氢借入过程提供了机会。