Chemoselective Electrochemical Oxidation of Secondary Alcohols using a Recyclable Chloride-Based Mediator

Synlett ◽  
2021 ◽  
Author(s):  
Florian Sommer ◽  
Oliver Kappe ◽  
David Cantillo
Keyword(s):  
Nitroxyl Radical ◽  
Supporting Electrolyte ◽  
Extraction Procedure ◽  
Hydroxyl Groups ◽  
Chloride Salt ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Oxidation Of Alcohols ◽  
Simple Extraction ◽  
Unsolved Issue

Selective anodic oxidation of alcohols in the presence of other functional groups can be accomplished using nitroxyl radical mediators. However, the electrochemical chemoselective oxidation of secondary alcohols in the presence of primary alcohols is an unsolved issue. Herein, we report an electrochemical procedure for the selective oxidation of secondary alcohols using an inexpensive chloride salt that acts as redox mediator and supporting electrolyte. The method is based on the controlled anodic generation of active chlorine species, which selectively oxidize secondary alcohols to the corresponding ketones when primary hydroxyl groups are present. The method has been demonstrated for a variety of substrates. The corresponding ketones were obtained in good to excellent yields. Moreover, the chloride salt can be easily recovered and reutilized by a simple extraction procedure, rendering the method highly sustainable

Revisiting Sodium Hypochlorite Pentahydrate (NaOCl·5H2O) for the Oxidation of Alcohols in Acetonitrile without Nitroxyl Radicals

Synlett ◽  
2018 ◽  
Vol 29 (18) ◽  
pp. 2404-2407 ◽  
Author(s):  
Tsunehisa Hirashita ◽  
Yuto Sugihara ◽  
Shota Ishikawa ◽  
Yohei Naito ◽  
Yuta Matsukawa ◽  
...  
Keyword(s):  
Sodium Hypochlorite ◽  
Nitroxyl Radicals ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Oxidation Of Alcohols

Sodium hypochlorite pentahydrate (NaOCl·5H2O) is capable of oxidizing alcohols in acetonitrile at 20 °C without the use of catalysts. The oxidation is selective to allylic, benzylic, and secondary alcohols. ­Aliphatic primary alcohols are not oxidized.

scholarly journals Biocatalytic Oxidation of Alcohols

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 952 ◽  
Author(s):  
Hendrik Puetz ◽  
Eva Puchľová ◽  
Kvetoslava Vranková ◽  
Frank Hollmann
Keyword(s):  
Selective Oxidation ◽  
State Of The Art ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Enantioselective Oxidation ◽  
Current State ◽  
Oxidation Of Alcohols ◽  
Enzymatic Methods

Enzymatic methods for the oxidation of alcohols are critically reviewed. Dehydrogenases and oxidases are the most prominent biocatalysts, enabling the selective oxidation of primary alcohols into aldehydes or acids. In the case of secondary alcohols, region and/or enantioselective oxidation is possible. In this contribution, we outline the current state-of-the-art and discuss current limitations and promising solutions.

The Dielectric Properties of Crystalline Long-Chain n-Primary Alcohols at Low Frequencies

1951 ◽  
Vol 4 (3) ◽  
pp. 365
Author(s):  
RJ Meakins ◽  
JW Mulley
Keyword(s):  
Dielectric Properties ◽  
Primary Alcohol ◽  
Dielectric Constants ◽  
Double Layers ◽  
Significant Feature ◽  
Hydroxyl Groups ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Dielectric Absorption ◽  
Long Chain

In a previous paper it was reported that certain crystalline forms of long-chain secondary alcohols show abnormally large dielectric absorption and dispersion of the dielectric constant at audio and radio frequencies. The present paper describes an extension of the investigation to n-primary alcohols and discusses the results in terms of the previously suggested theory of dielectric absorption due to the presence of hydrogen-bonded chains of hydroxyl groups. The most significant feature of the results is that the absorption is larger and occurs at much lower frequencies than for the secondary alcohols. This is considered to be due to the end-to-end arrangement of the molecules in n-primary alcohol crystals, which gives double layers of hydroxyl groups and enables the formation of more extensive hydrogen-bond chains. The dielectric constants at the lowest frequencies are almost as large as those previously reported by Hoffmann and Smyth (1949) for the " waxy " forms of n-primary alcohols. Further aspects described are the changes in dielectric properties during storage, the differences between the melted and recrystallized forms, and the effect of dispersing the molecules in an inert solid solvent. In each of these aspects the observed behaviour is similar to that previously reported for the secondary alcohols.

Oxidation of secondary alcohols and ethers by dimethyldioxirane

1999 ◽  
Vol 77 (3) ◽  
pp. 308-312 ◽  
Author(s):  
Alfons L Baumstark ◽  
Franci Kovac ◽  
Pedro C Vasquez
Keyword(s):  
Oxygen Atom ◽  
Methyl Ether ◽  
Radical Pair ◽  
Parent Compound ◽  
Activation Parameters ◽  
Silyl Ether ◽  
Secondary Alcohols ◽  
Benzyl Alcohols ◽  
Oxidation Of Alcohols ◽  
Direct Abstraction

The oxidation of several series of secondary alcohols 2-9, ethers 10-17, and related derivatives 18 and19, by dimethyldioxirane, 1, in acetone at 25°C produced the corresponding ketones in good to excellent yields for all but two cases. (The exceptions: oxidation of 1-methoxy-2-methyl-1-phenylpropane (48%) and 1-methoxy-2,2-dimethyl-1-phenylpropane (24%).) The oxidation of the secondary alcohols was found to yield k2 values that were roughly 10-fold greater than those of the corresponding methyl ethers. The rate constant for oxidation of a silyl ether was slightly lower than that for the corresponding methyl ether while that for the ester derivative was roughly half the value. For oxidation of alcohols and methyl ethers, the k2 values became smaller as the R " series (Me, Et, nPr, iPr, and tBu) increased in steric bulk (ρ* = 1.7; r = 0.998 and ρ* = 3.2; r = 0.95, respectively). The Hammett study for the oxidation of the methyl ethers of α-methyl-p-benzyl alcohols (10, 20-25) yielded a ρ value of -0.74. The activation parameters for oxidation of the parent compound of the ether series (1-methoxy-1-phenylethane) were ΔH‡ = 14.8 ± 0.5 kcal/mol, ΔS‡ = -21.9 eu, ΔG‡ = 21.3 kcal/mol, k2 (25°C) = 1.6 × 10-3 M-1 s-1. The mechanistic aspects of the oxidation are discussed in relation to two mechanistic extremes: (a) direct insertion of the oxygen atom into the C—H bond and (b) direct abstraction of the H by dimethyldioxirane to yield a caged-radical pair, with subsequent coupling to hemi-ketal intermediates that fragment to yield acetone, alcohol or water, and ketone as the final products.Key words: dimethyldioxirane, oxidation.

Ruthenium Pincer-Catalyzed Cross-Dehydrogenative Coupling of Primary Alcohols with Secondary Alcohols under Neutral Conditions

2012 ◽  
Vol 354 (13) ◽  
pp. 2403-2406 ◽  
Author(s):  
Dipankar Srimani ◽  
Ekambaram Balaraman ◽  
Boopathy Gnanaprakasam ◽  
Yehoshoa Ben-David ◽  
David Milstein
Keyword(s):  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Dehydrogenative Coupling ◽  
Neutral Conditions

scholarly journals Construction of a (NNN)Ru-Incorporated Porous Organic Polymer with High Catalytic Activity for β-Alkylation of Secondary Alcohols with Primary Alcohols

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 231
Author(s):  
Yao Cui ◽  
Jixian Wang ◽  
Lei Yu ◽  
Ying Xu ◽  
David J. Young ◽  
...  
Keyword(s):  
Functional Group ◽  
Catalytic Efficiency ◽  
Organic Polymer ◽  
Pincer Ligands ◽  
High Catalytic Activity ◽  
Secondary Alcohols ◽  
Primary Alcohols ◽  
Solid Supports ◽  
Porous Organic Polymer ◽  
Heterogeneous And Homogeneous Catalysis

Solid supports functionalized with molecular metal catalysts combine many of the advantages of heterogeneous and homogeneous catalysis. A (NNN)Ru-incorporated porous organic polymer (POP-bp/bbpRuCl3) exhibited high catalytic efficiency and broad functional group tolerance in the C–C cross-coupling of secondary and primary alcohols to give β-alkylated secondary alcohols. This catalyst demonstrated excellent durability during successive recycling without leaching of Ru which is ascribed to the strong binding of the pincer ligands to the metal ions.

Aerobic oxidation of primary alcohols in the presence of activated secondary alcohols

2005 ◽  
Vol 46 (5) ◽  
pp. 783-786 ◽  
Author(s):  
Hiromichi Egami ◽  
Hideki Shimizu ◽  
Tsutomu Katsuki
Keyword(s):  
Aerobic Oxidation ◽  
Secondary Alcohols ◽  
Primary Alcohols

One Pot Tandem Dual C=C and C=O Bond Reductions in β-Alkylation of Secondary Alcohols with Primary Alcohols by Ruthenium Complexes of Amido and Picolyl Functionalized N-Heterocyclic Carbenes

2021 ◽  
Author(s):  
A. P. Prakasham ◽  
Sabyasachi Ta ◽  
Shreyata Dey ◽  
Prasenjit Ghosh
Keyword(s):  
Ruthenium Complexes ◽  
Heterocyclic Carbenes ◽  
Secondary Alcohols ◽  
Coupling Reactions ◽  
Primary Alcohols ◽  
One Pot ◽  
The One ◽  
Alcohol Alcohol

Two different class of ruthenium complexes, namely, [1-mesityl-3-(2,6-Me2-phenylacetamido)-imidazol-2-ylidene]Ru(p-cymene)Cl (1c) and {[1-(pyridin-2-ylmethyl)-3-(2,6-Me2-phenyl)-imidazol-2-ylidene]Ru(p-cymene)Cl}Cl (2c), successfully carried out the one-pot tandem alcohol-alcohol coupling reactions of a variety of secondary and primary alcohols, in...

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