- Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
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A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
- Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
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supporting information
p. 10564 - 10567
(2021/10/19)
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- The inexpensive additive N-methylmorpholine effectively decreases the equivalents of nucleophiles in the catalytic highly enantioselective arylation of aryl aldehydes
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Highly enantioselective arylation of aryl aldehydes catalyzed by (S)-H8-BINOL-Ti(Oi-Pr)2 complex in the presence of N-methylmorpholine (NMM) as an effective and inexpensive additive is described for the first time. We found high enan
- Wang, Pei,Liu, Yue,Zhang, Ya-Lun,Da, Chao-Shan
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supporting information
p. 443 - 450
(2017/07/25)
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- General copper-catalyzed coupling of alkyl-, aryl-, and alkynylaluminum reagents with organohalides
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We report the first example of a very general Cu-catalyzed cross-coupling of organoaluminum reagents with organohalides. The reactions proceed for the couplings of alkyl-, aryl-, and alkynylaluminum reagents with aryl and heteroaryl halides and vinyl bromides, affording the cross-coupled products in good to excellent yields. Both primary and secondary alkylaluminum reagents can be utilized as organometallic coupling partners. These reactions are not complicated by β-hydride elimination, and as a result rearranged products are not observed with secondary alkylaluminum reagents even for couplings with heteroaryl halides under "ligand-free" conditions. Radical clock experiment with a radical probe and relative reactivity study of Ph3Al with two haloarenes, 1-bromonaphthalene and 4-chlorobenzonitrile, having two different redox potentials indicates that the reaction does not involve free aryl radicals and radical anions as intermediates. These results combined with the result of the Hammett plot obtained by reacting Ph3Al with iodoarenes containing p-H, p-Me, p-F, and p-CF3 substituents, which shows a linear curve (R2 = 0.99) with a ρ value of +1.06, suggest that the current transformation follows an oxidative addition-reductive elimination pathway.
- Shrestha, Bijay,Thapa, Surendra,Gurung, Santosh K.,Pike, Ryan A. S.,Giri, Ramesh
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p. 787 - 802
(2016/02/18)
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- Process for the Preparation of ?-C-Aryl Glucosides
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The present invention provides processes for stereoselectively preparing C-arylglucosides that can be useful as synthetic building block or drugs, including SGLT2 inhibitors.
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Paragraph 0354; 0355
(2014/05/20)
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- Tandem nucleophilic addition-Oppenauer oxidation of aromatic aldehydes to aryl ketones with triorganoaluminium reagents
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In the presence of pinacolone, the in situ prepared triorganoaluminium reagents reacted with aromatic aldehydes to give ketones in moderate to high yield. We propose that the products are formed via a tandem organoaluminium reagents addition-Oppenauer oxidation sequence. The Royal Society of Chemistry 2013.
- Fu, Ying,Yang, Yanshou,Hügel, Helmut M.,Du, Zhengyin,Wang, Kehu,Huang, Danfeng,Hu, Yulai
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supporting information
p. 4429 - 4432
(2013/08/23)
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- Synthesis and properties of calcium tetraorganylalanates with [Me 4-nAlPhn]- anions
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Triphenylalane yields in THF or Et2O the corresponding ether complexes [(thf)AlPh3] (1a) and [(Et2O)-AlPh3] (1b). The reaction of these triphenylalanes with phenylcalcium iodide in THF yielded quantitatively [(thf)5CaI][AlPh4] (2), which can be recrystallized from diethyl ether/THF mixtures without ether exchange reactions. The reaction of PhCa(thf)4I with trimethylalane in THF in an equimolar ratio leads to the formation of solvent-separated [(thf) 6Ca][AlMe3Ph]2 (5), which immediately shows ligand redistribution. Therefore, a fractionated crystallization gives [(thf)6Ca][AlMe2Ph2]2 (4) at 4°C, [(thf)4CaI2] at -20°C, and after reduction of the volume of the mother liquor [(thf)6Ca][AlMe3Ph] 2 (5) at -40°C and [(thf)6Ca][AlMe4] 2 (6) at -78°C. The formation of (thf)4Cal2 confirms that a Schlenk equilibrium is operative besides the ligand redistribution reactions. A solution of crystalline [(thf)6Ca] [AlMe2Ph2]2 (4) in THF shows 4 as the major component besides [(thf)6Ca][AlMe3Ph]2 (5) and [(thf)6Ca][AlMePh3]2 (3). With an increasing number of methyl groups the melting points decrease from 210°C for the tetraphenylalanate 2 to 20°C for the tetramethylalanate 6.
- Krieck, Sven,Goerls, Helmar,Westerhausen, Matthias
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p. 5052 - 5057
(2009/03/11)
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- 1,5-Asymmetric induction of chirality: Diastereoselective addition of organoaluminium reagents and allylstannanes into aldehyde groups in the side-chain of π-allyltricarbonyliron lactone complexes
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π-Allyltricarbonyliron lactone complex 5, bearing an aldehyde group in the side-chain, can be easily prepared from commercially available (2E,4E)-ethyl hexadienoate and reacts with organoaluminium and allylstannane nucleophiles to afford secondary alcohols. In analogy with the corresponding ketone-substituted complexes, the lactone tether acts via the Fe(CO)3 moiety as a source of asymmetric induction. The levels of diastereoselectivity are generally reduced, however, compared with those obtained using ketone complexes. This can be attributed, at least in part, to the carbonyl appendage adopting both s-cis and s-trans conformations. The level of 1,5-asymmetric induction is strongly dependent upon the nature of the nucleophile in the case of the organoaluminium reactions and upon the reaction temperature in the case of BF3-mediated addition of allylstannanes into the aldehyde group.
- Ley, Steven V.,Burckhardt, Svenja,Cox, Liam R.,Meek, Graham
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p. 3327 - 3337
(2007/10/03)
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- Redistribution Reactions Involving Lithium Aluminium Hydride and Lithium Tetraphenylaluminate
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Redistribution reactions involving LiAlH4 and LiAlPh4 were performed by mixing the reagents in appropriate ratios.The products: LiAlH3Ph, LiAlH2Ph2 and LiAlHPh3 were isolated and characterised by elemental analysis, infrared and nmr spectroscopy and DTA-TGA analysis.These products were also prepared by the reaction of PhLi with AlHnPh3-n (where n=1-3) in diethylether.Also PhAlH2 and Ph2AlH were prepared by the reaction of Ph3Al and AlH3 in both diethyl ether and THF in the appropriate stoichiometric ratios.
- Ashby, E. C.,Goel, A. B.
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p. 134 - 138
(2007/10/02)
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- Method of making aluminum alkyls
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A method of making aluminum alkyls utilizing an uncatalyzed exchange reaction wherein an aluminum trialkyl is reacted with an alkyl iodide in which the alkyl group differs from at least one of the alkyl groups of the aluminum trialkyl to form an aluminum trialkyl having the alkyl radical of the alkyl iodide reactant and an alkyl iodide having the alkyl radical of the aluminum trialkyl reactant. In particular, triethyl aluminum is reacted with methyl iodide to form trimethylaluminum and ethyl iodide. Aralkyl groups may be substituted for the alkyl groups to produce corresponding aralkyl compounds.
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