Rhodium-Catalyzed Heck-Type Coupling of Boronic Acids with Activated Alkenes in an Aqueous Emulsion
作者:Mark Lautens、John Mancuso、Harpreet Grover
DOI:10.1055/s-2004-829161
日期:——
Intermolecular couplings between arylboronic acids and activated alkenes catalyzed by a water-soluble tert-butyl amphosrhodium complex were found to progress at room temperature and generated Heck-type products with high yields and excellent selectivity. Substitution on the alkene component encouraged the formation of products arising from a conjugate addition-protonation process. In the case of Heck
Ligand-Free Nickel-Catalysed 1,4-Addition of Arylboronic Acids to α,β-Unsaturated Carbonyl Compounds
作者:Wen Chen、Lu Sun、Xi Huang、Jiayi Wang、Yanqing Peng、Gonghua Song
DOI:10.1002/adsc.201400761
日期:2015.5.4
catalytic system has been developed for the 1,4‐addition of arylboronic acids to α,β‐unsaturatedcarbonylcompounds. With catalyst loadings of 1–2 mol%, a series of 1,4‐adducts from chalcones and cinnamates was obtained in moderate to excellent yields within 5–30 min under a nitrogen atmosphere and microwave irradiation. The 1,4‐addition of arylboronic acids to acrylates is less efficient.
Synergistic N‐Heterocyclic Carbene/Palladium‐Catalyzed Umpolung 1,4‐Addition of Aryl Iodides to Enals
作者:Wenjun Yang、Bo Ling、Bowen Hu、Haolin Yin、Jianyou Mao、Patrick J. Walsh
DOI:10.1002/anie.201912584
日期:2020.1.2
promoted by cooperative (terpy)Pd/NHC catalysis was developed that generates various bioactive β,β-diaryl propanoate derivatives. This system is not only the first reported palladium-catalyzed arylation of NHC-bound homoenolates but also expands the scope of NHC-induced umpolung transformations. A diverse array of functional groups such as esters, nitriles, alcohols, and heterocycles are tolerated under
ligand-controlled nickel migration/arylation. This general protocol allows the use of abundant and bench-stable alkyl bromides and aryl bromides for the synthesis of a wide range of structurally diverse 1,1-diarylalkanes in excellent yields and high regioselectivities under mild conditions. We also demonstrated that alkyl bromide could be replaced by the proposed olefin intermediate while using n-propyl bromide/Mn0
Chiral olefin–sulfoxide as ligands for rhodium-catalyzed asymmetric conjugate addition of arylboronic acids to unsaturated esters
作者:Feng Xue、Dongping Wang、Xincheng Li、Boshun Wan
DOI:10.1039/c3ob41342j
日期:——
An efficient rhodium/olefin–sulfoxide catalyzed asymmetricconjugate addition of organoboronic acids to various unsaturatedesters has been developed, where 2-methoxy-1-naphthyl sulfinyl functionalized olefin ligands have been shown to be highly effective, and are especially applicable to unsaturated methyl esters with up to 99% yield and 91% ee.