22160-39-0Relevant academic research and scientific papers
Functionalization of α-C(sp3)?H Bonds in Amides Using Radical Translocating Arylating Groups
Radhoff, Niklas,Studer, Armido
supporting information, p. 3561 - 3565 (2021/01/04)
α-C?H arylation of N-alkylamides using 2-iodoarylsulfonyl radical translocating arylating (RTA) groups is reported. The method allows the construction of α-quaternary carbon centers in amides. Various mono- and disubstituted RTA-groups are applied to the arylation of primary, secondary, and tertiary α-C(sp3)?H-bonds. These radical transformations proceed in good to excellent yields and the cascades comprise a 1,6-hydrogen atom transfer, followed by a 1,4-aryl migration with subsequent SO2 extrusion.
Aerobic oxidation of aldehydes to acids with N-hydroxyphthalimide derivatives
Takamatsu, Keigo,Kasai, Miku,Nishizawa, Hinaru,Suzuki, Rio,Konno, Hiroyuki
, (2021/09/14)
The N-hydroxyphthalimide derivative-mediated aerobic oxidation of a selection of aldehydes to the corresponding carboxylic acids in air is described. This reaction proceeds via rearrangement of the Creigee (carboxylic peracid) intermediate and/or by the treatment of H2O and/or sulfides. Optimization of reaction conditions established NHNPI (14) as a mild catalyst for the oxidation reaction in MeCN under an atmosphere of air.
Preparation method of 2-R1 valeric acid
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, (2021/07/24)
The invention discloses a preparation method for 2-R1 valeric acid. The preparation method comprises the following steps: step 1, with methyl cyanoacetate as a starting material, adding bromopropane and sodium methoxide, carrying out a catalytic reaction, and conducting purifying to obtain 2-cyanomethyl valerate; step 2, subjecting 2-cyanomethyl valerate to a reaction under the catalysis of iodoalkane and sodium methoxide, and conducting aftertreatment to obtain 2-cyano-2-R1 methyl valerate; step 3, enabling the 2-cyano-2-R1 methyl valerate to undergo a reaction in an aqueous solution of sulfuric acid at 120-160 DEG C for 15-40 hours so as to obtain a mixture of 2-R1 valeric acid and 2-R1 methyl valerate; and step 4, hydrolyzing the mixture by using an aqueous sodium hydroxide solution to obtain 2-R1 sodium valerate and methanol, and conducting acidifying by using inorganic acid to obtain 2-R1 valeric acid. Reagents adopted in the preparation method are relatively common, and the risk of the reagents is relatively low; and reaction conditions are mild, and the temperature is easier to control relatively. The invention develops a purification process of the key intermediate 2-cyanomethyl valerate, and the process flow is simple.
Ruthenium-catalysed hydroxycarbonylation of olefins
Dühren, Ricarda,Kucmierczyk, Peter,Jackstell, Ralf,Franke, Robert,Beller, Matthias
, p. 2026 - 2030 (2021/04/09)
State-of-the-art catalyst systems for hydroxy- and alkoxycarbonylations of olefins make use of palladium complexes. In this work, we report a complementary ruthenium-catalysed hydroxycarbonylation of olefins applying an inexpensive Ru-precursor (Ru3(CO)12) and PCy3as a ligand. Crucial for the success of this transformation is the use of hexafluoroisopropanol (HFIP) as the solvent in the presence of an acid co-catalyst (PTSA). Overall, moderate to good yields are obtained using aliphatic olefins including the industrially relevant substrate di-isobutene. This atom-efficient catalytic transformation provides straightforward access to various carboxylic acids from unfunctionalized olefins.
Cobalt-Catalyzed Asymmetric Hydrogenation of α,β-Unsaturated Carboxylic Acids by Homolytic H2 Cleavage
Chirik, Paul J.,Shevlin, Michael,Zhong, Hongyu
supporting information, (2020/03/13)
The asymmetric hydrogenation of α,β-unsaturated carboxylic acids using readily prepared bis(phosphine) cobalt(0) 1,5-cyclooctadiene precatalysts is described. Di-, tri-, and tetra-substituted acrylic acid derivatives with various substitution patterns as well as dehydro-α-amino acid derivatives were hydrogenated with high yields and enantioselectivities, affording chiral carboxylic acids including Naproxen, (S)-Flurbiprofen, and a d-DOPA precursor. Turnover numbers of up to 200 were routinely obtained. Compatibility with common organic functional groups was observed with the reduced cobalt(0) precatalysts, and protic solvents such as methanol and isopropanol were identified as optimal. A series of bis(phosphine) cobalt(II) bis(pivalate) complexes, which bear structural similarity to state-of-the-art ruthenium(II) catalysts, were synthesized, characterized, and proved catalytically competent. X-band EPR experiments revealed bis(phosphine)cobalt(II) bis(carboxylate)s were generated in catalytic reactions and were identified as catalyst resting states. Isolation and characterization of a cobalt(II)-substrate complex from a stoichiometric reaction suggests that alkene insertion into the cobalt hydride occurred in the presence of free carboxylic acid, producing the same alkane enantiomer as that from the catalytic reaction. Deuterium labeling studies established homolytic H2 (or D2) activation by Co(0) and cis addition of H2 (or D2) across alkene double bonds, reminiscent of rhodium(I) catalysts but distinct from ruthenium(II) and nickel(II) carboxylates that operate by heterolytic H2 cleavage pathways.
Palladium-Catalyzed C(sp3)-H Nitrooxylation with tert-Butyl Nitrite and Molecular Oxygen
Han, Ye-Qiang,Li, Bo,Shi, Bing-Feng,Yang, Xu
supporting information, p. 9719 - 9723 (2020/12/21)
Herein, we report a Pd(II)-catalyzed nitrooxylation of unactivated methyl C(sp3)-H bonds using commercial available and easily manageable tert-butyl nitrite as the precursor of ONO2 radical under aerobic conditions. Environmentally benign molecular oxygen is used to initiate the generation of active radical reactant; it is also used as the terminal oxidant. A broad range of nitrooxylated aliphatic carboxamides were prepared in moderate to good yields under mild conditions.
Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
, (2020/07/20)
Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
PROCESSES FOR PREPARING 4-METHYL-5-NONANONE AND 4-METHYL-5-NONANOL
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Paragraph 0120-0122, (2020/07/14)
The present invention provides a process for preparing 4-methyl-5-nonanone of the following formula (3): the process comprising at least a step of subjecting 2-methylpentanoic anhydride of the following formula (1) and an n-butyl nucleophilic reagent of the following general formula (2) in which M represents Li, MgZ1, or ZnZ1, wherein Z1 represents a halogen atom or an n-butyl group, to a nucleophilic substitution. reaction Coproduce 4-methyl-5-nonanone (3), as well as a process for preparing 4-methyl-5-nonanol of the following formula (5), the process comprising at least steps of preparing 4-methyl-5-nonanone; and subjecting the obtained 4-methyl-5-nonanone and a reducing agent to a reduction reaction to produce 4-methyl-5-nonanol (5).
Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information, p. 14365 - 14373 (2019/09/06)
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
Carboxylation of benzylic and aliphatic C-H bonds with CO2 induced by light/ketone/nickel
Ishida, Naoki,Masuda, Yusuke,Imamura, Yuuya,Yamazaki, Katsushi,Murakami, Masahiro
supporting information, p. 19611 - 19615 (2019/12/24)
A photoinduced carboxylation reaction of benzylic and aliphatic C-H bonds with CO2 is developed. Toluene derivatives capture gaseous CO2 at the benzylic position to produce phenylacetic acid derivatives when irradiated with UV light in the presence of an aromatic ketone, a nickel complex, and potassium tert-butoxide. Cyclohexane reacts with CO2 to furnish cyclohexanecar-boxylic acid under analogous reaction conditions. The present photoinduced carboxylation reaction provides a direct access from readily available hydrocarbons to the corresponding carboxylic acids with one carbon extension.
