1192-62-7Relevant articles and documents
Preparation and Degradation of Rhodium and Iridium Diolefin Catalysts for the Acceptorless and Base-Free Dehydrogenation of Secondary Alcohols
Buil, Mariá L.,Collado, Alba,Esteruelas, Miguel A.,G? mez-Gallego, Mar,Izquierdo, Susana,Nicasio, Antonio I.,Onìate, Enrique,Sierra, Miguel A.
, p. 989 - 1003 (2021)
Rhodium and iridium diolefin catalysts for the acceptorless and base-free dehydrogenation of secondary alcohols have been prepared, and their degradation has been investigated, during the study of the reactivity of the dimers [M(μ-Cl)(I4-C8H12)]2 (M = Rh (1), Ir (2)) and [M(μ-OH)(I4-C8H12)]2 (M = Rh (3), Ir (4)) with 1,3-bis(6′-methyl-2′-pyridylimino)isoindoline (HBMePHI). Complex 1 reacts with HBMePHI, in dichloromethane, to afford equilibrium mixtures of 1, the mononuclear derivative RhCl(I4-C8H12){κ1-Npy-(HBMePHI)} (5), and the binuclear species [RhCl(I4-C8H12)]2{μ-Npy,Npy-(HBMePHI)} (6). Under the same conditions, complex 2 affords the iridium counterparts IrCl(I4-C8H12){κ1-Npy-(HBMePHI)} (7) and [IrCl(I4-C8H12)]2{μ-Npy,Npy-(HBMePHI)} (8). In contrast to chloride, one of the hydroxide groups of 3 and 4 promotes the deprotonation of HBMePHI to give [M(I4-C8H12)]2(μ-OH){μ-Npy,Niso-(BMePHI)} (M = Rh (9), Ir (10)), which are efficient precatalysts for the acceptorless and base-free dehydrogenation of secondary alcohols. In the presence of KOtBu, the [BMePHI]- ligand undergoes three different degradations: Alcoholysis of an exocyclic isoindoline-N double bond, alcoholysis of a pyridyl-N bond, and opening of the five-membered ring of the isoindoline core.
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Hartough,Kosak
, p. 3093,3095 (1947)
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Comparison of 2-acetylfuran formation between ribose and glucose in the Maillard reaction
Wang, Yu,Ho, Chi-Tang
, p. 11997 - 12001 (2008)
Sugar type is a major factor regulating the reaction rates and pathways in Maillard reaction. Ribose and glucose were used to compare their reactivities and pathways of 2-acetylfuran formation. A stable isotope labeling method was used to study their reactivity. A 1:1 mixture of [13C 6]glucose and unlabeled ribose (or other unlabeled sugar) was reacted with proline at 145 °C for 40 min. The reactivity of each sugar was revealed by the ratio of isotopomers. The reactivity of sugars in 2-acetylfuran formation decreased in the order ribose, fructose, glucose, rhamnose, and sucrose. This method simplified the reaction system and the calculation process and gave a direct comparison of reactivity as seen via mass spectrum. The difference between glucose and ribose in 2-acetylfuran formation was that glucose could form 2-acetylfuran directly from cyclization of its intact carbon skeleton, whereas ribose first underwent degradation into fragments before forming a six-carbon unit leading to 2-acetylfuran. In the presence of cysteine, ribose could not generate 2-acetylfuran at a detectable level. When ribose was reacted with glycine, formaldehyde generated from glycine combined with ribose to form 2-acetylfuran. In other amino acids, a symmetric structure of the ribose intermediate was formed, making fragmentation more complicated.
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Hartough,Kosak
, p. 867 (1948)
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Enantioselective microbial oxidation of 1-arylethanol in an organic solvent
Nakamura, Kaoru,Inoue, Yuko,Ohno, Atsuyoshi
, p. 4375 - 4376 (1994)
Reactivity in enantioselective oxidation of 1-arylethanol by Geotrichum candidum is improved when the microbe is entrapped with a water-adsorbent polymer and the reaction is conducted in hexane. Cyclohexanone as an additive improves the rate of oxidation as well as ee of the remained alcohol.
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Hartough,Kosak
, p. 2639 (1946)
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Potassium ferrate on wet alumina: Preparation and reactivity
Caddick,Murtagh,Weaving
, p. 9365 - 9373 (2000)
The use of a wet alumina/potassium ferrate system for the oxidation of a range of activated alcohols is described. Studies are presented which delineate the scope and limitation of the procedure and include a new carbon-carbon bond cleavage reaction. (C) 2000 Elsevier Science Ltd.
Iron–PNP-Pincer-Catalyzed Transfer Dehydrogenation of Secondary Alcohols
Budweg, Svenja,Wei, Zhihong,Jiao, Haijun,Junge, Kathrin,Beller, Matthias
, (2019)
The well-defined iron PNP pincer complex catalyst [Fe(H)(BH4)(CO)(HN{CH2CH2P(iPr)2}2] was used for the catalytic dehydrogenation of secondary alcohols to give the corresponding ketones. Using acetone as inexpensive hydrogen acceptor enables the oxidation with good to excellent yields. DFT computations indicate an outer-sphere mechanism and support the importance of an acceptor to achieve this transformation under milder conditions.
CtD strategy to construct stereochemically complex and structurally diverse compounds from griseofulvin
Li, Yu,Liu, Gong-Qing,Zhao, Rui-Han,Zhao, Yu,Zhu, Li
supporting information, p. 10755 - 10758 (2021/10/20)
The Complexity to Diversity (CtD) strategy, a strategy for the synthesis of stereochemically complex and structurally diverse small molecules from natural products using ring-distortion reactions, was applied in the synthesis of a 47-member compound collection from the natural product griseofulvin. A Tsuji-Trost allylation and oxa-Michael cyclization tandem reaction was used for the first time in the CtD strategy to generate complex ring fused compounds.
Selective oxidation of alkenes to carbonyls under mild conditions
Huo, Jie,Xiong, Daokai,Xu, Jun,Yue, Xiaoguang,Zhang, Pengfei,Zhang, Yilan
supporting information, p. 5549 - 5555 (2021/08/16)
Herein, a practical and sustainable method for the synthesis of aldehydes, ketones, and carboxylic acids from an inexpensive olefinic feedstock is described. This transformation features very sustainable and mild conditions and utilizes commercially available and inexpensive tetrahydrofuran as the additive, molecular oxygen as the sole oxidant and water as the solvent. A wide range of substituted alkenes were found to be compatible, providing the corresponding carbonyl compounds in moderate-to-good yields. The control experiments demonstrated that a radical mechanism is responsible for the oxidation reaction.
