cas 765-43-5, Cyclopropyl methyl ketone | Articles data

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(Di)triazolylidene manganese complexes in catalytic oxidation of alcohols to ketones and aldehydes
Carbonyl manganese complexes with chelating or bridging mesoionic di(1,2,3-triazolylidene) ligands were efficiently synthesised and fully characterised, including the X-ray diffraction study of a bimetallic manganese(0) complex. This unprecedented bimetallic complex displayed high yield and selectivity in the catalytic oxidation of secondary alcohols and benzyl alcohol with tert-butyl hydroperoxide under mild conditions.
Pinto, Mara F.,Olivares, Marta,Vivancos, ángela,Guisado-Barrios, Gregorio,Albrecht, Martin,Royo, Beatriz
p. 2421 - 2425
(2019)
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(±)-Camphor sulfonic acid assisted IBX based oxidation of 1° and 2° alcohols
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Kumar, Kamlesh,Joshi, Penny,Rawat, Diwan S
(2021/09/02)

Method for synthesizing cyclopropyl methyl ketone
The synthesis method, uses :1) methylfuran as the raw material 2 - to obtain,chloro - 2 2-pentanone, and the method comprises the following steps ;2): carrying out hydrogen hydrolysis 1) through one-pot hydrogenation hydrolysis, in the presence of the hydrogenation catalyst 5 - hydrogen and water.3). The method 2) for synthesizing the cyclopropylmethyl ketone according to step 5 - comprises the following steps: preparing the cyclopropylmethyl ketone, through a one-pot hydrogenation hydrolysis reaction and a ring-closing reaction step. to prepare the cyclopropylmethyl ketone, by a one-pot, hydrogenation hydrolysis reaction. 2 - The method comprises the following steps: synthesizing,methyl furan as, a raw material, through a one- pot 2 - hydrogenation hydrolysis reaction and, a ring- closing reaction to, prepare the. cyclopropylmethyl ketone by a one- pot hydrogenation hydrolysis reaction and a ring-closing reaction to obtain the cyclopropylmethyl ketone.
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Paragraph 0029; 0031; 0034; 0035; 0038; 0039; 0042

(2020/03/17)

Safe and environment-friendly preparation method of cyclopropyl acetylene
The invention relates to the field of medicine synthesis, and discloses a safe and environment-friendly preparation method of cyclopropylacetylene, which comprises the following steps: 1) performing chlorination reaction; 2) carrying out an ethynylation reaction; and 3) synthesizing cyclopropyl methyl ketone from the by-product E/Z-2, 5-dichloro-2-pentene. The process provided by the invention ishigh in chlorination yield; the chlorination reagent is triphosgene, the reaction condition is mild, and the safety is high. An organic solvent, inorganic base and a phase transfer catalyst system areadopted in the ethynylation reaction, and the yield is high; the high-flash-point organic solvent dilutes the reaction system, and the reaction is safe. E/Z-2-5-dichloro-2-pentene generated through the chlorination reaction is subjected to sulfuric acid dechlorination and cyclization and then converted into cyclopropyl methyl ketone, and application is achieved. Potassium chloride is treated as aby-product, and an organic solvent, water, organic alkali and a catalyst are used in chlorination reaction; an organic solvent and a phase transfer catalyst used in the ethynylation reaction can be recycled. The reaction is environment-friendly, only two potassium salt byproducts of potassium chloride and potassium sulfate are formed, and zero emission is basically realized.
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Paragraph 0037; 0043; 0057; 0063

(2020/08/22)

Preparation method of 1-chloro-1-chloroacetyl cyclopropane
The invention provides a preparation method of 1-chloro-1-chloroacetyl cyclopropane. The preparation method comprises the following steps: 1)reacting 1, 3-butadiene with diazomethane to generate vinylcyclopropane; 2)reacting the vinyl cyclopropane with an oxidation reagent to generate acetyl cyclopropane; and 3)reacting the acetyl cyclopropane with a chlorination reagent to generate the target product 1-chloro-1-chloroacetyl cyclopropane. The method can reduce the use of strong acids, strong bases and chlorination reagents in the preparation of the 1-chloro-1-chloroacetyl cyclopropane, thereby reducing the discharge of three wastes and lowering the safety risk, and can enhance the synthesis yield to adapt to industrial production.
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Paragraph 0035; 0036

(2020/04/17)

IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild reaction conditions
An efficient, practical and facile procedure has been developed for the oxidation of primary and secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature. The reaction affords quantitative yields of the corresponding carbonyl compounds without the formation of over oxidized products. The present synthetic protocol is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. The developed synthetic protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 g scale in higher yields by a simple filtration process.
Kumar, Kamlesh,Kumar, Prashant,Joshi, Penny,Rawat, Diwan S
supporting information

(2020/03/04)

Preparation method of 2-chloro-1-(1-chlorocyclopropyl) acetone
The invention relates to the technical field of chemical synthesis, and particularly discloses a preparation method of 2-chloro-1-(1-chlorocyclopropyl) acetone. The preparation method comprises the following steps: enabling alpha-acetyl-gamma butyrolactone and hydrochloric acid to have an open-loop decarboxylic reaction to obtain 5-chloro-2-pentanone; adding the 5-chloro-2-pentanone and a catalystinto an alkaline solution, implementing a cyclization reaction, obtaining cyclopropyl methyl ketone; implementing a chlorination reaction with a chloride agent to obtain the 2-chloro-1-(1-chlorocyclopropyl) acetone. The reaction steps of the provided method are less, the reaction period is short, the yield is more than 70%, and the content of the 2-chloro-1-(1-chlorocyclopropyl) acetone in a product is more than 95%.
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Paragraph 0029; 0032; 0034; 0037; 0039; 0042; 0044; 0047

(2019/05/28)

Photolysis of Tp′Rh(CNneopentyl)(PhNCNneopentyl) in the presence of ketones and esters: Kinetic and thermodynamic selectivity for activation of different aliphatic C-H bonds
The active fragment [Tp′Rh(CNneopentyl)], generated from the precursor Tp′Rh(CNneopentyl)(PhNCNneopentyl), underwent oxidative addition of substituted ketones and esters resulting in Tp′Rh(CNneopentyl)(R)(H) complexes (Tp′ = tris-(3,5-dimethylpyrazolyl)borate). These C-H activated complexes underwent reductive elimination at varying temperatures (24-70 °C) in C6D6 or C6D12. Using previously established kinetic techniques, the relative Rh-C bond strengths were calculated. Analysis of the relative Rh-C bond strengths vs. C-H bond strengths shows a linear correlation with slope RM-C/C-H = 1.22 (12). In general, α-substituents increase the relative Rh-C bond strengths compared to the C-H bond that is broken.
Jones, William D.,Parsons, Astrid M.
supporting information
p. 10945 - 10952
(2019/08/01)

Synthesis method of primary amine hydrochloride
The invention discloses a synthesis method of primary amine hydrochloride. According to the synthesis method, in the presence of a gold complex, water and alkyne carry out catalytic hydrolysis to generate ketones, and then ketones and ammonium formate are catalyzed by a rhodium complex to generate primary amine. Compared with a conventional primary amine synthesis method, the synthesis method hasthe advantages that no alkali is added during the reaction process, no side product is generated, the atomic economy is good, the reaction conditions are mild, and the synthesis method has a wide prospect.
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Paragraph 0114-0117

(2019/03/09)

Chemoselective Oxidation of Equatorial Alcohols with N-Ligated λ3-Iodanes
The site-selective and chemoselective functionalization of alcohols in complex polyols remains a formidable synthetic challenge. Whereas significant advancements have been made in selective derivatization at the oxygen center, chemoselective oxidation to the corresponding carbonyls is less developed. In cyclic systems, whereas the selective oxidation of axial alcohols is well known, a complementary equatorial selective process has not yet been reported. Herein we report the utility of nitrogen-ligated (bis)cationic λ3-iodanes (N-HVIs) for alcohol oxidation and their unprecedented levels of selectivity for the oxidation of equatorial over axial alcohols. The conditions are mild, and the simple pyridine-ligated reagent (Py-HVI) is readily synthesized from commercial PhI(OAc)2 and can be either isolated or generated in situ. Conformational selectivity is demonstrated in both flexible 1,2-substituted cyclohexanols and rigid polyol scaffolds, providing chemists with a novel tool for chemoselective oxidation.
Mikhael, Myriam,Adler, Sophia A.,Wengryniuk, Sarah E.
supporting information
p. 5889 - 5893
(2019/08/26)

Transfer-dehydrogenation of secondary alcohols catalyzed by manganese NNN-pincer complexes
Novel catalytic systems based on pentacarbonylmanganese bromide and stable NNN-pincer ligands are presented for the transfer-dehydrogenation of secondary alcohols to give the corresponding ketones in good to excellent isolated yields. Best results are obtained using di-picolylamine derivatives as ligands and acetone as an inexpensive hydrogen acceptor. Besides high activity for benzylic substrates, aliphatic alcohols, as well as steroid derivatives, are readily oxidized in the presence of the optimal phosphorus-free catalyst.
Budweg, Svenja,Junge, Kathrin,Beller, Matthias
supporting information
p. 14143 - 14146
(2019/12/02)

Method for synthesizing cyclopropyl methyl ketone by using Alpha-acetyl-Gamma-butyrolactone high-boiling substance
The invention relates to the technical field of chemical synthesis and especially relates to a method for synthesizing cyclopropyl methyl ketone by using Alpha-acetyl-Gamma-butyrolactone high-boilingsubstance. The method for synthesizing cyclopropyl methyl ketone by using Alpha-acetyl-Gamma-butyrolactone high-boiling substance comprises the following steps: (a) uniformly mixing zeolite and concentrated hydrochloric acid, and then adding the high-boiling substance, and reacting for 1-5h while keeping temperature at 80-100 DEG C; standing by and layering after the ending of reaction, and collecting an oil layer; (b) heating an alkaline solution to 70-90 DEG C, adding the oil layer acquired in step (a), and then reacting for 1-5h while keeping temperature at 80-100 DEG C; standing by and layering after the ending of reaction, and collecting the oil layer, thereby acquiring cyclopropyl methyl ketone. According to the invention, three-dimensional well-aligned porous material zeolite and concentrated hydrochloric acid are uniformly mixed with each other, so that the contact area of Alpha-acetyl-Gamma-butyrolactone in high-boiling substance and hydrochloric acid is increased, yield of 5-chlorine-2-pentanone and cyclopropyl methyl ketone is increased and production of by-products is reduced.
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Paragraph 0048-0122

(2019/04/10)

Recyclable Pd-contained perovskite catalyst synthesized by a low temperature hydrothermal method for aerobic alcohol oxidation
We successfully prepared Pd-containing perovskite strontium titanate (Pd-STO) by a relatively low-temperature hydrothermal method (i.e., 373 K) without posterior calcination. The particle size and porosity of the STO perovskite could be tuned by changing the molar ratio of H2O/NH3 (e.g., 5.0, 12.5 and 25.0) during the preparation of the amorphous titania sources. The mesoporous contained Pd-STO(12.5) showed superior catalytic performance compared to that of the other Pd-STO(x) (x = H2O/NH3) perovskites for alcohol oxidation with molecular oxygen. Both the refluxing of the non-polar solvents and addition of molecular sieves enhanced the reaction yield significantly. The Pd-incorporated perovskite (Pd-STO) showed better recyclability compared with that of the impregnated perovskite (imp-Pd/STO).
Saputra, Leo,Kojima, Takashi,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
p. 132 - 138
(2018/05/23)

Design and Assembly of a Chiral Metallosalen-Based Octahedral Coordination Cage for Supramolecular Asymmetric Catalysis
Supramolecular containers featuring both high catalytic activity and high enantioselectivity represent a design challenge of practical importance. Herein, it is demonstrated that a chiral octahedral coordination cage can be constructed by using twelve enantiopure Mn(salen)-derived dicarboxylic acids as linear linkers and six Zn4-p-tert-butylsulfonylcalix[4]arene clusters as tetravalent four-connected vertices. The porous cage features a large hydrophobic cavity (≈3944 ?3) decorated with catalytically active metallosalen species and is shown to be an efficient and recyclable asymmetric catalyst for the oxidative kinetic resolution of racemic secondary alcohols and the epoxidation of olefins with up to >99 % enantiomeric excess. The cage architecture not only prevents intermolecular deactivation and stabilizes the Mn(salen) catalysts but also encapsulates substrates and concentrates reactants in the cavity, resulting in enhanced reactivity and enantioselectivity relative to the free metallosalen catalyst.
Tan, Chunxia,Jiao, Jingjing,Li, Zijian,Liu, Yan,Han, Xing,Cui, Yong
supporting information
p. 2085 - 2090
(2018/02/06)

Biocatalytic Racemization Employing TeSADH: Substrate Scope and Organic Solvent Compatibility for Dynamic Kinetic Resolution
Racemization in combination with a kinetic resolution is the base for a dynamic kinetic resolution (DKR). Biocatalytic racemization was successfully performed for a broad scope of sec-alcohols by employing a single alcohol dehydrogenase (ADH) variant from Thermoanaerobacter pseudoethanolicus (formerly T. ethanolicus; TeSADH W110A I86A C295A). The catalyst employed as a lyophilized whole cell preparation or cell free extract, which tolerated various non-water miscible organic solvents under micro-aqueous or two-phase conditions, whereby cyclohexane and n-hexane suited best. Various concepts for combining the enzymatic racemization with an enzymatic kinetic resolution to achieve overall a bis-enzymatic DKR were evaluated. A proof of concept showed a successful DKR with racemization in aqueous phase combined with acylation in the organic phase.
Pop?oński, Jaros?aw,Reiter, Tamara,Kroutil, Wolfgang
p. 763 - 768
(2018/02/27)

Preparing method of cyclopropyl methyl ketone
The invention provides a preparing method of cyclopropyl methyl ketone. The method includes the steps that 2-methyl furan generates a hydrogenation under the condition that a hydrogenation catalyst and hydrogen exist to prepare 2-methyl-4,5-dihydrofuran, and after a hydrogenation catalyst in a reaction mass is removed, the 2-methyl-4,5-dihydrofuran is subject to a isomerization reaction under the condition that an isomerization catalyst exists and the temperature ranges from 10 DEG C to 100 DEG C to obtain the cyclopropyl methyl ketone. According to the preparing method, the production period of a product is short, reactions are free of process waste water, the catalysts can be recycled and reused, and the preparing method is particularly suitable for replacing the process that the cyclopropyl methyl ketone is generated through the 2-methyl furan after multi-step reactions.
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Paragraph 0009; 0031; 0034-0035; 0038; 0041; 0044; 0047

(2017/08/28)

Preparation method of novel anti-ultraviolet plastic additive
The invention discloses a preparation method of a novel anti-ultraviolet plastic additive and belongs to the technical field of plastic additive synthesis. The novel anti-ultraviolet plastic additive has a structure described in the specification, wherein R1 is an oxygen atom or nitrogen atom; and R2 is cyclopentane, cyclobutane or cyclopropane; and R3 is methyl, ethyl or phenyl. The invention also discloses a preparation method of the novel anti-ultraviolet plastic additive. According to the invention, a new anti-ultraviolet plastic additive is synthesized by virtue of a new method, reaction process operation is simple and practicable, raw materials are cheap and available, reaction efficiency is relatively high and repeatability is relatively good, and the novel anti-ultraviolet plastic additive has a good anti-ultraviolet radiation ageing effect on plastic.
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Paragraph 0019; 0020; 0021

(2017/11/29)

Ketone synthesis method through alkyne hydrolysis
The invention discloses a ketone synthesis method through alkyne hydrolysis. The method comprises the following steps: adding alkyne, a catalyst [(IPr)AuCl], a solvent methanol, and water into a reactor, carrying out reactions for several hours at a temperature of 110 to 120 DEG C, cooling to the room temperature, carrying out rotary evaporation to remove the solvent, and performing column separation to obtain target compounds. Compared with conventional ionic gold catalyst, the provided method directly uses gold chloride [(IPr)AuCl] as the catalyst, alkyne is hydrolyzed into ketone, the yield is high, the selectivity is complete, and thus the method has an important meaning for organic synthesis and environment protection.
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Paragraph 0103-0106

(2017/05/02)

An environmentally benign hydration of alkynes catalyzed by gallic acid/tannic acid in water
A gallic acid catalyzed hydration strategy from alkynes under mild conditions has been developed. The catalyst system exhibits excellent activity, thus avoiding the use of any transition metal, strong acids or other toxic reagent as cocatalysts. Recycling experiments were conducted, and this procedure can be scaled up. Other tannins such as tannic acid can also be applied in this reaction which shows the potential utilization of natural feedstocks.
Deng, Tao,Wang, Cheng-Zhang
p. 7029 - 7032
(2016/10/07)

Gold nanoparticles supported on magnesium oxide nanorods for oxidation of alcohols
Gold nanoparticles supported on magnesium oxide nanorods (Au-MgO) have been synthesised by a solution based chemical reduction method. Au-MgO nanorods were found to be an efficient heterogeneous catalyst for oxidation of alcohols with hydrogen peroxide in aqueous medium at room temperature. To find out the best reaction conditions for oxidation, optimization of catalyst quantity, solvent, mole equivalence of hydrogen peroxide were carried out. The scope of the reaction was extended to several aromatic and aliphatic alcohols, product yields were quantified by gas chromatography (GC) and GC/mass spectroscopy. Heterogeneity and reusability tests were performed. The use of water as a solvent and hydrogen peroxide as co-catalyst at room temperature makes the reaction interesting from sustainable development point of view.
Emayavaramban,Ganesh Babu,Karvembu,Kadirvelu,Dharmaraj
p. 2517 - 2526
(2016/03/19)

A process for the preparation of cyclopropyl methyl ketone (by machine translation)
The invention relates to a process for the preparation of cyclopropyl methyl ketone, belonging to the field of organic synthesis. The preparation method comprises the following steps: the metal halide and an inert solvent is added in to the fixed bed reactor, and then the fixed bed reactor is heated to 185-195°C, to the fixed bed in the reactor is then continuously added α-acetyl-γ-butyrolactone, the α-acetyl-γ-butyrolactone generating cracking reaction; after the saturation, when the reaction, cease adding α-acetyl-γ-butyrolactone, to continue reaction distillation until no distilled product, cyclopropyl methyl ketone obtained crude; is connected with the rectifying tower on a fixed bed reactor, the cyclopropyl methyl are of the first flow to the rectifying tower tower, then atmospheric distillation, adjusting the reflux ratio, separation of impurities, of high purity-cyclopropyl methyl ketone. The invention has low production cost, high production efficiency, product yield and high purity, there are few by-products, less waste waste water, environmental pollution is small, is more suitable for industrial production. (by machine translation)
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Paragraph 0042-0043; 0048-0050; 0059

(2017/03/08)

Expanding Substrate Specificity of ω-Transaminase by Rational Remodeling of a Large Substrate-Binding Pocket
Production of structurally diverse chiral amines via biocatalytic transamination is challenged by severe steric interference in a small active site pocket of ω-transaminase (ω-TA). Herein, we demonstrated that structure-guided remodeling of a large pocket by a single point mutation, instead of excavating the small pocket, afforded desirable alleviation of the steric constraint without deteriorating parental activities toward native substrates. Molecular modeling suggested that the L57 residue of the ω-TA from Ochrobactrum anthropi acted as a latch that forced bulky substrates to undergo steric interference with the small pocket. Removal of the latch by a L57A substitution allowed relocation of the small pocket and dramatically improved activities toward various arylalkylamines and alkylamines (e.g., 1100-fold increase in kcat/KM for α-propylbenzylamine). This approach may provide a facile strategy to broaden the substrate specificity of ω-TAs.
Han, Sang-Woo,Park, Eul-Soo,Dong, Joo-Young,Shin, Jong-Shik
p. 2712 - 2720
(2015/09/01)

Regioselective hydration of terminal alkynes catalyzed by a neutral gold(I) complex [(IPr)AuCl] and one-pot synthesis of optically active secondary alcohols from terminal alkynes by the combination of [(IPr)AuCl] and Cp?RhCl[(R, R)-TsDPEN]
A neutral gold(I) complex [(IPr)AuCl] (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene) was found to be a highly effective catalyst for the hydration of terminal alkynes, including aromatic alkynes and aliphatic alkynes. The desired methyl ketones were obtained in high yields with complete regioselectivities. Furthermore, a series of optically active secondary alcohols could be obtained in high yield with good to excellent enatioselectivities via one-pot sequential hydration/asymmetric transfer hydrogenation (ATH) from terminal alkynes by the combination of of [(IPr)AuCl] and Cp?RhCl[(R,R)-TsDPEN] (Cp? = pentamethylcyclopentadienyl, TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine). Notably, this research exhibited the potential of the direct use of neutral gold(I) complexes instead of cationic ones as catalysts for the activation of multiple bonds for organic synthesis.
Li, Feng,Wang, Nana,Lu, Lei,Zhu, Guangjun
p. 3538 - 3546
(2015/04/14)

Highly Efficient Oxidation of Secondary Alcohols to Ketones Catalyzed by Manganese Complexes of N4 Ligands with H2O2
The manganese complex Mn(S-PMB)(CF3SO3)2 was proven to be highly efficient in the catalytic oxidation of several benzylic and aliphatic secondary alcohols with H2O2 as the oxidant and acetic acid as the additive. A maximum turnover number of 4700 was achieved in the alcohol oxidation. In addition, the Hammett analysis unveiled the electrophilic nature of this manganese catalyst with N4 ligand. (Chemical Equation Presented).
Shen, Duyi,Miao, Chengxia,Xu, Daqian,Xia, Chungu,Sun, Wei
supporting information
p. 54 - 57
(2015/07/28)

4-CH3CONH-TEMPO/Peracetic Acid System for a Shortened Electron-Transfer-Cycle-Controlled Oxidation of Secondary Alcohols
We have developed a 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) derivative catalyzed oxidation of secondary alcohols with peracetic acid as the oxidant, which was generated from H2O2 and acetic acid catalyzed by strongly acidic resins. The oxidation of alcohols proceeded well through a shortened electron-transfer cycle under metal-free conditions, avoiding the use of any other electron-transfer mediators such as halides. In addition, we demonstrated that the present system exhibited excellent efficiency under mild conditions for the oxidation of aromatic, aliphatic, and allylic secondary alcohols. Shortcut to ketones: The 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-derivative-catalyzed oxidation of secondary alcohols employing peracetic acid generated from H2O2 and acetic acid with strongly acidic resins proceeds through a shortened electron-transfer cycle without halide additives. The system not only exhibits excellent efficiency at room temperature but also has a wide substrate scope.
Zhang, Shufang,Miao, Chengxia,Xia, Chungu,Sun, Wei
p. 1865 - 1870
(2015/06/23)

Synthesis of a-Alkylated Ketones via Tandem Acceptorless Dehydrogenation/a-Alkylation from Secondary and Primary Alcohols Catalyzed by Metal-Ligand Bifunctional Iridium Complex [CpIr(2,2′-bpyO)(H2O)]
A new strategy for the synthesis of α-alkylated ketones via tandem acceptorless dehydrogenation/α-alkylation from secondary and primary alcohols was proposed and accomplished. In the presence of metal-ligand bifunctional iridium complex [CpIr(2,2′-bpyO)(H2O)], various desirable products were obtained in high yields. Compared with previous methods for the direct dehydrogenative coupling of secondary alcohols with primary alcohols to α-alkylated ketones, this protocol has obvious advantages including complete selectivity for α-alkylated ketones and more environmentally benign conditions. Notably, the study also exhibited the potential to develop tandem reactions catalyzed using a metal-ligand bifunctional iridium complex.
Wang, Rongzhou,Ma, Juan,Li, Feng
p. 10769 - 10776
(2015/11/18)

METHOD FOR PRODUCING OPTICALLY ACTIVE ALPHA-SUBSTITUTED PROLINE
The present invention aims to provide an industrial method practically suitable for producing optically active α-substituted prolines from an acyclic ketone compound by a small number of steps under mild conditions. The present invention relates to a production method of an optically active α-substituted proline (4) and/or an optically active α-substituted prolinamide (5), including (a) reacting an acyclic ketone compound (1) with at least one selected from ammonia, an ammonium salt, primary amine and a salt of primary amine, and a cyanating agent to give a cyclic nitrogen-containing compound (2), (b) hydrating the cyclic nitrogen-containing compound (2) to give an α-substituted prolinamide (3), and (c) resolving the α-substituted prolinamide (3) by one or more of (d) enzymatical hydrolysis, (e) resolution by diastereomeric salt formation, and (f) separation by column chromatography.
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Paragraph 0239; 0240

(2014/05/06)

Aerobic oxidation of secondary alcohols using NHPI and iron salt as catalysts at room temperature
Aerobic oxidation of various alcohols has been accomplished by using a novel catalytic system, N-hydroxyphthalimide (NHPI) combined with Fe(NO 3)3·9H2O. Secondary alcohols, especially benzylic and aliphatic alcohols, were smoothly transformed into corresponding ketones with up to 92% yields at room temperature under one atmosphere pressure of oxygen. The influences of reaction conditions such as solvent, different metal catalyst, catalyst loading and the structure of alcohols on the promotion effect were studied. And a possible radical mechanism for the oxidation of secondary alcohols in Fe(NO3)3·9H 2O/NHPI/O2 system was proposed.
Zhao, Hanqing,Sun, Wei,Miao, Chengxia,Zhao, Quanyi
p. 62 - 67
(2014/07/08)

Efficient oxidation of secondary alcohols to ketones by NaOCl catalyzed by salen-Mn(III)/NBS
An efficient catalytic system salen-Mn(III)/NBS for oxidation of secondary alcohols to ketones by inexpensive and readily available oxidizing agent NaOCl has been developed. The process resulted in good to excellent yields under the action of 2 mol % of salen-Mn(III) and 13 mol % of NBS at room temperature. However, such system was not efficient in oxidation of secondary benzyl alcohols with a strong electronicdonating substituent attached to the benzene ring due to bromination of the alcohols.
Zhang,Lü,Cui,Zhao
p. 2021 - 2026
(2015/02/02)

ω-Transaminase-catalyzed kinetic resolution of chiral amines using l-threonine as an amino acceptor precursor
Kinetic resolution of chiral amines using l-threonine as a cosubstrate was demonstrated by a biocatalytic strategy in which (S)-selective ω-transaminase (ω-TA) was coupled with threonine deaminase (TD), eliminating the need to use an expensive keto acid as an amino acceptor. The coupled enzyme reaction enabled simultaneous production of enantiopure (R)-amine and l-homoalanine which are pharmaceutically important building blocks. To extend the versatility of this strategy to production of both enantiomers of chiral amines, (R)-selective ω-TA coupled with TD was employed to produce (S)-amine.
Malik, M. Shaheer,Park, Eul-Soo,Shin, Jong-Shik
supporting information; experimental part
p. 2137 - 2140
(2012/09/25)

Enantioselective oxidation of racemic secondary alcohols catalyzed by chiral Mn(iii)-salen complexes with N-bromosuccinimide as a powerful oxidant
We demonstrate an efficient enantioselective oxidation of secondary alcohols catalyzed by Mn(iii)-salen complex using N-bromosuccinimide (NBS) as the oxidant. The new protocol is very efficient for the oxidative kinetic resolution of a variety of secondary alcohols, including ortho-substituted benzylic alcohols. The Royal Society of Chemistry 2012.
Xu, Daqian,Wang, Shoufeng,Shen, Zhiqiang,Xia, Chungu,Sun, Wei
supporting information
p. 2730 - 2732
(2012/11/07)

Tris-chelate complexes of cobalt(III) with N-[di(alkyl/aryl)carbamothioyl] benzamide derivatives: Synthesis, crystallography and catalytic activity in TBHP oxidation of alcohols
New six coordinated tris-chelate cobalt(III) complexes of the type [Co(L)3] (1-4) {where HL = N-[di(alkyl/aryl)carbamothioyl]benzamide derivatives}were prepared from the reaction between CoCl2· 6H2O and N-[di(alkyl/aryl)carbamothioyl]benzamide in ethanol and characterized by elemental analysis and spectral data (UV/Vis, IR, 1H & 13C NMR). The molecular structure of a representative complex [Co(L1)3] (1) [where HL1 = N-(diisopropylcarbamothioyl)benzamide], was determined by single crystal X-ray diffraction method and reveals a distorted octahedral geometry and a facial configuration of S atoms around the Co(III) center. These complexes act as efficient catalysts for the oxidation of alcohols to their corresponding aldehydes or ketones in presence of tert-butyl hydroperoxide (TBHP) at 80°C.
Gunasekaran,Jerome,Ng, Seik Weng,Tiekink, Edward R.T.,Karvembu
experimental part
p. 156 - 162
(2012/02/16)

The palladium-catalyzed aerobic kinetic resolution of secondary alcohols: Reaction development, scope, and applications
The first palladium-catalyzed enantioselective oxidation of secondary alcohols has been developed, utilizing the readily available diamine (-)-sparteine as a chiral ligand and molecular oxygen as the stoichiometric oxidant. Mechanistic insights regarding the role of the base and hydrogen-bond donors have resulted in several improvements to the original system. Namely, addition of cesium carbonate and tert-butyl alcohol greatly enhances reaction rates, promoting rapid resolutions. The use of chloroform as solvent allows the use of ambient air as the terminal oxidant at 23°C, resulting in enhanced catalyst selectivity. These improved reaction conditions have permitted the successful kinetic resolution of benzylic, allylic, and cyclopropyl secondary alcohols to high enantiomeric excess with good-toexcellent selectivity factors. This catalyst system has also been applied to the desymmetrization of meso-diols, providing high yields of enantioenriched hydroxyketones.
Ebner, David C.,Bagdanoff, Jeffrey T.,Ferreira, Eric M.,McFadden, Ryan M.,Caspi, Daniel D.,Trend, Raissa M.,Stoltz, Brian M.
supporting information; experimental part
p. 12978 - 12992
(2010/06/19)

Preparation of (R)-amines from racemic amines with an (S)-amine transaminase from Bacillus megaterium
Screening was carried out to identify strains useful for the preparation of (R)-1-cyclopropylethylamine and (R)-sec-butylamine by resolution of the racemic amines with an (S)-specific transaminase. Several Bacillus megaterium strains from our culture collection as well as several soil isolates were found to have the desired activity for the resolution of the racemic amines to give the (R)-enantiomers. Using an extract of the best strain, Bacillus megaterium SC6394, the reaction was shown to be a trans-amination requiring pyruvate as amino acceptor and pyridoxal phosphate as a cofactor. Initial batches of both amines were produced using whole cells of Bacillus megaterium SC6394. The transaminase was purified to homogeneity to obtain N-terminal as well as internal amino acid sequences. The sequences were used to design polymerase chain reaction (PCR) primers to enable cloning and expression of the trans-aminase in E. coli SC16578. In contrast to the original B. megaterium process, pH control and aeration were not required for the resolution of sec-butyl-amine and an excess of pyruvate was not consumed by the recombinant cells. The resolution of sec-butylamine (0.68M) using whole cells of E. coli SC16578 was scaled up to give (R)-sec-butylamine·1/2 H2SO 4 in 46.6% isolated yield with 99.2% ee. An alternative isolation procedure was also used to isolate (R)-secbutylamine as the free base.
Hanson, Ronald L.,Davis, Brian L.,Chen, Yijun,Goldberg, Steven L.,Parker, William L.,Tully, Thomas P.,Montana, Michael A.,Patel, Ramesh N.
experimental part
p. 1367 - 1375
(2009/06/18)

Efficient and selective Al-catalyzed alcohol oxidation via oppenauer chemistry
A highly active and selective Al-based catalytic Oppenauer (O) oxidation is reported. Quantitative and selective oxidations of a variety of benzylic, propargylic, allylic, and aliphatic primary and secondary alcohols were achieved using nitrobenzaldehyde derivatives as the oxidant and simple aluminum compounds as precatalysts. Copyright
Graves, Christopher R.,Zeng, Bi-Shun,Nguyen, SonBinh T.
p. 12596 - 12597
(2008/02/03)

Insight into the mechanism of oxidative kinetic resolution of racemic secondary alcohols by using manganese(III)(salen) complexes as catalysts
The oxidative kinetic resolution of various racemic secondary alcohols with PhI(OAc)2 catalyzed by chiral [MnIII(salen)] complexes in the presence of KBr was studied in a water/organic solvent mixture. The dramatic, synergetic effect of additives, organic solvent, and the substituents of chiral salen ligands on the enantioselectivities of the reactions is reported. Results from UV/Vis spectroscopy and ESI-MS studies provide evidence that these reactions are induced by the formation of a high-valent manganese intermediate.
Li, Zhen,Tang, Zhong H.,Hu, Xiao X.,Xia, Chun G.
p. 1210 - 1216
(2007/10/03)

Biomimetic alcohol oxidations by an iron(III) porphyrin complex: Relevance to cytochrome P-450 catalytic oxidation and involvement of the two-state radical rebound mechanism
The systematic oxidation reactions of a wide range of alcohols have been carried out by using an iron porphyrin complex in order to understand their relation to cytochrome P-450 enzymes and to have a practical application to organic synthesis. The iron porphyrin complex catalyzed efficiently alcohol oxidation to the respective carbonyl compound via a high-valent iron-oxo porphyrin intermediate ((Porp)Fe=O+). Several mechanistic studies such as isotope 18O labeling, deuterium isotope effect, linear free energy relationship, and ring-opening of radical clock substrate, have suggested that the alcohol is oxidized by a sequence of reactions involving an a-hydroxyalkyl radical intermediate and oxygen rebound to form the gem-diol, dehydration of which yields the carbonyl compounds. Moreover, it has been proposed that a two-state reactivity mechanism can also be adopted for alcohol oxidation reactions in iron porphyrin model systems as exhibited by P-450 enzymes.
Han, Jung Hee,Yoo, Sang-Kun,Seo, Jin Soo,Hong, Sung Jin,Kim, Seok Kyu,Kim, Cheal
p. 402 - 406
(2007/10/03)

Scope of enantioselective Palladium(II)-catalyzed aerobic alcohol oxidations with (-)-sparteine
Evaluation of the substrate scope for Pd(II)/ (-)-sparteine catalyzed aerobic oxidative kinetic resolution of secondary alcohols is disclosed. An improved system is found with use of tert-butyl alcohol solvent in which benzylic and aliphatic alcohols as well as alcohols containing olefins are effectively oxidatively resolved. For substrates that successfully undergo oxidative kinetic resolution, krel values are generally between 10 and 20. Successful scale-up of various substrates to 10-mmol scale is described. Extension to oxidative desymmetrization of 1,3-meso-diols is successful with enantiomeric excesses ranging from 78 to 85%.
Mandal, Sunil K.,Jensen, David R.,Pugsley, Jacob S.,Sigman, Matthew S.
p. 4600 - 4603
(2007/10/03)

Palladium-catalyzed aerobic oxidative kinetic resolution of alcohols with an achiral exogenous base
Substitution of exogenous (-)-sparteine for a more practical achiral base in the aerobic oxidative kinetic resolution of secondary alcohols is described. Carbonate bases are the most effective of those screened and allow for effective kinetic resolution of benzylic, allylic, and aliphatic substrates. The procedure was also successfully extended to the oxidative desymmetrization of meso diols.
Mandal, Sunil K.,Sigman, Matthew S.
p. 7535 - 7537
(2007/10/03)

Catalyst structure for ketone production and method of making and using the same
A catalyst structure and method of making and using the same in a ketone production process. The catalyst structure includes a substantial theoretical monolayer of catalyst on a catalyst support to optimize ketone yield and weight hourly space velocities.
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Page column 9-12

(2008/06/13)

PROCESS FOR THE CONVERSION OF CARBOXYLIC ACIDS TO KETONES
Disclosed is a process for the preparation of ketones by contacting one or more carboxylic acids with a niobium catalyst at elevated temperatures. The process includes the use of a modified base-exchanged niobium catalyst that is particularly useful for the production of cyclopropyl ketones such as cyclopropyl methyl ketone from cyclopropanecarboxylic acid and acetic acid.
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Table V

(2010/11/29)

The Mn(acac)3-RCN-CCl4 system as a new efficient reagent for the oxidation of secondary alcohols into ketones
The Mn(acac)3-RCN-CCl4 system was found to be efficient for the oxidation of secondary alcohols into the corresponding ketones in 80-93% yields. The oxidation proceeds through the formation of alkyl hypochlorites, which are generated from CCl4 and the alcohols in the presence of the Mn(acac)3-RCN catalytic system (R = Me, Et, and Ph).
Khusnutdinov,Schadneva,Baiguzina,Dzhemilev
p. 1065 - 1067
(2007/10/03)

Oxidation of Isopropylcyclopropane by Chromyl Chloride: Ring-Opened Products Support a Hydrogen Atom Abstraction Mechanism
Chromyl chloride (CrO2Cl2) reacts with neat isopropylcyclopropane at 65 °C to give a dark precipitate along with at least 20 organic products. Both cyclopropyl products and ring-opened products are observed: 2-cyclopropyl-2-chloropropane (1,0.4% yield based on chromium), 2-cyclopropyl-2-propanol (2, 0.2%), 5-chloro-2-methyl-2-pentene (3, 0.3%), and 4-methyl-3-penten-1-ol (4, 0.5%) as well as other ring-opened products. Authentic samples of 1-4 were synthesized, and their GC and GC/ MS data were compared with the reaction mixture. Other organic products (5-10) were tentatively assigned by GC/MS on the basis of their m / z and fragmentation patterns. The ratio of (1 + 2) vs (3 + 4) increases by a factor of 2 when the initial concentration of CrO2Cl2 increases from 0.3 to 1.12 M. The reaction was also carried out in the gas phase, and essentially all the products from the liquid phase reaction were observed. The products are explained by a mechanism involving initial hydrogen atom abstraction from the substrate. The resulting dimethylcyclopropylcarbinyl radical can either be trapped by CrO2Cl2 (to form 1 and 2) or ring-open to give 4-methyl-3-pentenyl radical, which reacts with CrO2Cl2 to form 3 and 4 as well as further oxidized products. The oxidation of isopropylcyclopropane by MnO4- in pyridine was also examined. Acetone, an expected ring-opened product, was the only product observed by our analytical techniques. Me2C18O is produced from 18O-labeled MnO4-. These results suggest that the reactions of CrO2Cl2 and MnO4- with isopropylcyclopropane proceed by hydrogen atom transfer to form organic radical intermediates.
Wang, Kun,Mayer, James M.
p. 4248 - 4252
(2007/10/03)

Isomerization of 2-Methyl-4,5-dihydrofuran. Studies with a Single-Pulse Shock Tube
The isomerization of 2-methyl-4,5-dihydrofuran was studied behind reflected shock waves in a pressurized driver single-pulse shock tube over the temperature range 805-1030 K and densities of approximately ca 3*10-5 mol/cm3.Two isomerization products, acetylcyclopropane and 3-penten-2-one, are obtained in the isomerization.Acetylcyclopropane is formed in an irreversible process from 2-methyl-4,5-dihydrofuran.It further isomerizes, at higher temperatures, to cis- and trans-3-penten-2-one.At high temperatures where the conversion of 2-methyl-4,5-dihydrofuran is high, the main source for 3-penten-2-one is acetylcyclopropane.At lower temperatures 3-penten-2-one is formed mainly by a direct isomerization of 2-methyl-4,5-dihydrofuran.A small concentration of decomposition products, mainly methane and ethane, are also found in shock mixtures of 2-methyl-4,5-dihydrofuran, particularly at high temperatures.The Arrhenius relations for the tree aforementioned processes are as follows: 2-methyl-4,5-dihydrofuran -> acetylcyclopropane, k1=1015.4 exp(-56.8*103/RT) s-1; 2-methyl-4,5-dihydrofuran -> 3-penten 2-one, k2=1015.7 exp(-63.6*103/RT) s-1; acetylcyclopropane -> 3-penten-2-one, k3=1014.4 exp(-58.3*103/RT) s-1, where R is expressed in units of cal/(K mol).
Lifshitz, Assa,Laskin, Alexander
p. 2341 - 2345
(2007/10/02)

Studies on the Catalytic Oxidation of Alkanes and Alkenes by Titanium Silicates
Titanium containing, aluminum-free ZSM-5 (TS-1) and amorphous TiO2-SiO2 coprecipitate are investigated as catalysts for the selective oxidation of alkanes and alkenes using a variety of oxidants at temperatures below 100 deg C. Comparisons between the activities of TS-1 and the TiO2-SiO2 coprecipitate for alkane oxidation and alkene epoxidation using nonaqueous H2O2 indicate that the absence of water is crucial for the catalytic activity of silica-supported titanium. Due to the hydrophobicity of TS-1, the concentration of water surrounding the titanium is maintained at a low value, and thus TS-1 can be used as an oxidation catalyst with aqueous H2O2 as oxidant. Alkyl hydroperoxides are active as oxidants for alkene epoxidation on the TiO2-SiO2 coprecipitate but not for alkane oxidation reactions on both TS-1 and the TiO2-SiO2 coprecipitate. A plausible explanation for the above results is provided. The presence of stereoscrambling without any "radical clock" rearrangement during alkane oxidation on TS-1 indicates that the radicals formed may have a very short life-time, or their movements are restricted such that no rearrangement can occur. A proposal for the mechanism of alkane oxidation on TS-1 is given and compared to a mechanism suggested for alkene epoxidation on TS-1 and the TiO2-SiO2 coprecipitate.
Khouw, C. B.,Dartt, C. B.,Labinger, J. A.,Davis, M. E.
p. 195 - 205
(2007/10/02)

Reaction of bis(trifluoromethyl)amino-oxyl with t-butylbenzene, 2,2-diphenylpropane, benzylcyclopropane and some related alcohols
Reaction of the oxyl (CF3)2NO(.) (1) with t-butylbenzene (c. 3:1 molar ratio) at room temperature gives the hydroxylamine (CF3)2NOH (3) (43percent on oxyl) and a multicomponent higher-boiling mixture containing the substitution product (CF3)2NOCH2CMe2Ph (3) (28percent on arene), and the compounds 3-(CF3)2NC6H4CMe3 (5) (8percent on arene) and 4-(CF3)2NC6H4CMe3 (6) (6percent on arene).The reaction with 2,2-diphenylpropane (c. 4:1 molar ratio) at 70-80 deg C affords hydroxylamine 3 (45percent on oxyl) and a complex higher-boiling mixture, from which only the substitution product (CF3)2NOCH2CMePh2 (7) (36percent on arene) could be isolated.In contrast, the reaction of oxyl 1 with benzylcyclopropane at room temperature is clean and gives hydroxylamine 3 (49percent on oxyl) and the substitution product (8) (95percent on cyclopropane).From the reactions of oxyl 1 with 2-phenylpropan-2-ol (2:1 molar ratio), cyclopropylmethanol (c. 4:1 molar ratio) and 1-cyclopropylethanol (2:1 molar ratio) at room temperature, apart from hydroxylamine 3, the isolated products are a mixture of dimers of α-methylstyrene (10-12) (30percent on ol) and the 2:1 adduct of oxyl 1 and α-methylstyrene, i.e. (CF3)2NOCH2CMe(Ph)ON(CF3)2 (9) (50percent on ol); the ester (13) (99percent on ol); and the ketone (15) (60percent on ol), respectively.
Connelly Gregory D.,Tipping, Anthony E.
p. 111 - 116
(2007/10/02)

ACYL TRANSFER REACTIONS WITH PHOSPHINE OXIDES: SYNTHESIS OF E-HOMOALLYLIC ALCOHOLS, CYCLOPROPYL KETONES, AND γ-HYDROXY KETONES
Esters of 3-hydroxypropylphosphine oxides rearrange in base by O to C acyl (RCO) transfer to give the hydroxy ketones (8). threo-Selective reduction of (8) leads to pure E-homoallylic alcohols whilst C to O acyl )Ph2PO) transfer leads to γ-hydroxy ketones with nucleophilic aqueous base or cyclopropyl ketones with BuOKt - HOBut.
Wallace, Paul,Warren, Stuart
p. 2971 - 2978
(2007/10/02)

Oxidation of Secondary Alcohols with t-Butyl Hypochlorite in the Presence of Pyridine
When treated with t-butyl hypochlorite and pyridine in methylene dichloride, secondary alcohols give the corresponding ketones in very high yield.The relative reactivities of a number of p-substituted 1-phenylethanols containing electron-donating and -withdrawing substituents were investigated.Oxidation of cis- and trans-4-t-butylcyclohexanol, as well as some other cycloalkanols, proceeds with the same relative rate.On the basis of this and other data a cyclic transition state and loss of α-hydrogen of the starting alcohols as hydride ion are proposed as characteristics of the reaction mechanism.
Milovanovic, Jovan N.,Vasojevic, Miorad,Gojkovic, Svetislav
p. 533 - 536
(2007/10/02)

Heterometallic Catalysts for the Oxidation of Alcohols - (R = CH3, CH2SiMe3)
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Zhang, Naijie,Mann, Charles M.,Shapley, Patricia A.
p. 6591 - 6592
(2007/10/02)

On the Isomerization of 2-AC5H8Cl2lkoxy-2-methyl-1-methylenecyclopropanes to 1-Alkoxy-1-cyclopropylethenes
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Baldwin, John E.,Ghatlia, Naresh D.,Lundbaeck, Karin M. O.
p. 698 - 700
(2007/10/02)