1851-93-0Relevant articles and documents
Ligand-free Guerbet-type reactions in air catalyzed by in situ formed complexes of base metal salt cobaltous chloride
Kumar, Akshai,Kumar, Pradhuman,Nandi, Pran Gobinda
, p. 1100 - 1108 (2022/03/02)
Inexpensive, earth-abundant and environmentally benign cobaltous chloride efficiently accomplishes the catalytic β-alkylation of alcohols in air at 140 °C. At higher loadings of cobaltous chloride (1 mol%) in the presence of 2.5 mol% NaOtBu, there is a rapid formation of heterogeneous Co nanoparticles (NPs) which are apparently sensitive to air and result in poor yields (ca. 25%) of β-alkylated products. In contrast, performing the reaction in an argon atmosphere under otherwise identical conditions leads to higher yields (ca. 44%). The heterogenization and eventual loss of activity in air could be delayed by operating at a lower (0.01 mol%) CoCl2 loading in the presence of 2.5 mol% NaOtBu at 140 °C. Under these conditions, the catalytic β-alkylation of alcohols proceeded with high yields (up to 89%) and unprecedented turnovers (ca. 8900). Mechanistic studies are indicative of the involvement of catalysts based on in situ generated molecular Co complexes of alcohols. Labelling studies provide key evidence for the involvement of C-H activation in the cobaltous chloride catalyzed β-alkylation with a KIE of 1.61. Kinetic studies indicate linear dependence of the rate on the concentration of cobaltous chloride and sodium t-butoxide along with a non-linear dependence on the concentration of 1-phenyl ethanol and benzyl alcohol.
RETRACTED ARTICLE: The Manganese(I)-Catalyzed Asymmetric Transfer Hydrogenation of Ketones: Disclosing the Macrocylic Privilege
Passera, Alessandro,Mezzetti, Antonio
supporting information, p. 187 - 191 (2019/12/11)
The bis(carbonyl) manganese(I) complex [Mn(CO)2(1)]Br (2) with a chiral (NH)2P2 macrocyclic ligand (1) catalyzes the asymmetric transfer hydrogenation of polar double bonds with 2-propanol as the hydrogen source. Ketones (43 substrates) are reduced to alcohols in high yields (up to >99 %) and with excellent enantioselectivities (90–99 % ee). A stereochemical model based on attractive CH–π interactions is proposed.
PROCESS FOR THE PREPARATION OF ALKOXYLATES COMPOSITIONS
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Page/Page column 23-25, (2019/06/17)
A mixture of two alkoxylates surfactants, one being an aryl aliphatic carbinol alkoxylate, the other one being a dialiphatic carbinol alkoxylate, said mixture being useful for stabilizing emulsions and dispersions used in agricultural or pharmaceutical formulations. The alkoxylates surfactants may serve as substitutes for nonylphenol ethoxylates (NPE) and tristyrylphenol ethoxylates (TSE).