- Commercially available neat organozincs as highly reactive reagents for catalytic enantioselective addition to ketones and aldehydes under solvent free conditions
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Neat Et2Zn, Ph2Zn, and highly concentrated Me 2Zn are highly reactive organozinc reagents, which are commercially available in bulk quantities. We here report a catalytic enantioselective Et2Zn, Ph2Zn, and Me2Zn addition to ketones and aldehydes under solvent free or highly concentrated conditions without Ti(Oi-Pr)4 as a conventional activator of organozinc reagents. The desired optically active tertiary and secondary alcohols were obtained in good yield with high enantioselectivity when compared to the conventional solvent-use conditions. From the viewpoint of ecological and environmental reasons in green chemistry, this catalysis would be practical for not only academic but also industrial use.
- Hatano, Manabu,Mizuno, Tomokazu,Ishihara, Kazuaki
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experimental part
p. 4417 - 4424
(2011/08/06)
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- Solvent effects on the steric course of the solvolysis of tertiary acyclic derivatives
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The solvolysis of (R)-3-chloro-3,7-dimethyloctane (2), of the corresponding hydrogen phthalate (S)-4g, and of the p-nitrobenzoate (S)-4h proceeds with up to 87% inversion of configuration in solvents such as methanol or ethanol. The degree of inversion decreases in more dissociating solvents. In 2,2,2-trifluoroethanol (TFE), up to 40% retention of configuration occurs.
- Mueller, Paul,Rossier, Jean-Claude
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p. 2232 - 2237
(2007/10/03)
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- Highly enantiospecific oxyfunctionalization of nonactivated hydrocarbon sites by perfluoro-cis-2-n-butyl-3-n-propyloxaziridine
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(equation presented) Nonactivated hydrocarbon sites of enantiopure compounds are oxyfunclionalized enantiospecifically by perfluoro-cis-2-n-butyl-3-n-propyloxaziridine under remarkably mild reaction conditions. The reaction occurs with retention of configuration at the oxidized stereogenic center, and the enantiospecificity is highly independent from both the carbon framework of the substrate and the presence of functional groups.
- Arnone, Alberto,Foletto, Stefania,Metrangolo, Pierangelo,Pregnolato, Massimo,Resnati, Giuseppe
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p. 281 - 284
(2008/02/14)
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