alumina is found to promote the conjugate addition of indoles to nitroalkenes in solventlessconditions at 60 °C. Nitroalkenes can be replaced by nitro alcohols that are converted into nitroolefins under the reaction conditions. Alternatively, a tandem nitroaldol-dehydration allows the utilization of nitroalkanes and aldehydes as remote precursors of reactive nitroalkenes in a ‘one–pot’ synthesis of 3-substituted
A highly regioselective N-1 and C-2 diacylation of 3-substituted indoles with arylglyoxal hydrates to afford N-1 and C-2 indolyl diketones in moderate to good yields is described. Notably, the control of regioselectivity is achieved by small changes in the Cu catalyst, additive and solvent. Importantly, the intermediates for N-1 and C-2 diacylation were detected and two plausible pathways were also
Synthesis, structural characterization of benzimidazole-functionalized Ni(II) and Hg(II) N-heterocyclic carbene complexes and their applications as efficient catalysts for Friedel–Crafts alkylations
作者:Guoli Huang、Hongsheng Sun、Xiaojie Qiu、Yingzhong Shen、Juli Jiang、Leyong Wang
DOI:10.1016/j.jorganchem.2011.04.039
日期:2011.9
L1 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)methyl)imidazolyl-idene), [Ni(L2)2(CH3CN)](PF6)2 (3b, L2 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)-methyl)benzimidazolylidene), and [Hg(L1)2(CH3CN)2](PF6)2 (4) have been successfully prepared and fully characterized by NMR, ESI-MS spectroscopy, and X-ray diffraction analysis. The nickelcomplexes reveal
Temperature Dual Enantioselective Control in a Rhodium-Catalyzed Michael-Type Friedel-Crafts Reaction: A Mechanistic Explanation
作者:Isabel Méndez、Ricardo Rodríguez、Víctor Polo、Vincenzo Passarelli、Fernando J. Lahoz、Pilar García-Orduña、Daniel Carmona
DOI:10.1002/chem.201601301
日期:2016.7.25
enantiomer of the Friedel–Crafts (FC) adduct of the reaction between N‐methyl‐2‐methylindole and trans‐β‐nitrostyrene can be obtained by using (SRh,RC)‐[(η5‐C5Me5)Rh(R)‐Prophos}(H2O)][SbF6]2 as the catalyst precursor. This catalytic system presents two other uncommon features: 1) The ee changes with reaction time showing trends that depend on the reaction temperature and 2) an increase in the catalyst
Chalcogen Bonding Catalysis of a Nitro‐Michael Reaction
作者:Patrick Wonner、Alexander Dreger、Lukas Vogel、Elric Engelage、Stefan M. Huber
DOI:10.1002/anie.201910639
日期:2019.11.18
Chalcogen bonding is the non-covalent interaction between Lewis acidic chalcogen substituents and Lewis bases. Herein, we present the first application of dicationic tellurium-based chalcogen bonddonors in the nitro-Michael reaction between trans-β-nitrostyrene and indoles. This also constitutes the first activation of nitro derivatives by chalcogen bonding (and halogenbonding). The catalysts showed