873-76-7Relevant academic research and scientific papers
Hydrogenation of Esters by Manganese Catalysts
Li, Fu,Li, Xiao-Gen,Xiao, Li-Jun,Xie, Jian-Hua,Xu, Yue,Zhou, Qi-Lin
, (2022/01/13)
The hydrogenation of esters catalyzed by a manganese complex of phosphine-aminopyridine ligand was developed. Using this protocol, a variety of (hetero)aromatic and aliphatic carboxylates including biomass-derived esters and lactones were hydrogenated to primary alcohols with 63–98% yields. The manganese catalyst was found to be active for the hydrogenation of methyl benzoate, providing benzyl alcohol with turnover numbers (TON) as high as 45,000. Investigation of catalyst intermediates indicated that the amido manganese complex was the active catalyst species for the reaction. (Figure presented.).
Silver-Catalyzed Hydroboration of C-X (X = C, O, N) Multiple Bonds
Pandey, Vipin K.,Tiwari, Chandra Shekhar,Rit, Arnab
supporting information, p. 1681 - 1686 (2021/03/03)
AgSbF6 was developed as an effective catalyst for the hydroboration of various unsaturated functionalities (nitriles, alkenes, and aldehydes). This atom-economic chemoselective protocol works effectively under low catalyst loading, base- A nd solvent-free moderate conditions. Importantly, this process shows excellent functional group tolerance and compatibility with structurally and electronically diverse substrates (>50 examples). Mechanistic investigations revealed that the reaction proceeds via a radical pathway. Further, the obtained N,N-diborylamines were showcased to be useful precursors for amide synthesis.
CeO2-nanocubes as efficient and selective catalysts for the hydroboration of carbonyl groups
Bhawar, Ramesh,Bose, Shubhankar Kumar,Patil, Kiran S.
supporting information, p. 15028 - 15034 (2021/09/04)
The CeO2-nanoparticle catalysed hydroboration of carbonyl compounds with HBpin (pin = OCMe2CMe2O) is reported to afford the corresponding borate esters in excellent yield. A series of aromatic and aliphatic aldehydes and ketones having synthetically important functional groups were well-Tolerated under mild reaction conditions. Further, chemoselective hydroboration of aldehydes over other reducible functional groups such as ketone, nitrile, hydroxide, alkene, alkyne, amide, ester, nitro, and halides was achieved. Importantly the catalyst can be recycled up to ten runs with slight loss in activity. This journal is
A method of synthesis of alcohols
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Paragraph 0067-0072, (2022/01/10)
The present invention belongs to the field of organic synthesis technology, specifically a synthesis method of an alcohol; the present invention is under the catalytic action of tert-butanol lithium, with ester compounds and pinacol borane as raw materials, tetrahydrofuran as a solvent, reacted at 100 ° C for 24h, followed by adding 2mol / LNaOH / MeOH solution, stirred at room temperature overnight to obtain alcohol compounds; the raw materials of the present invention are of extensive sources or easy to prepare, the reaction conditions are relatively mild and do not require a large number of / cumbersome additives, in addition to the tert-butanol lithium catalyst is simple, And the prepared alcohol compounds are of high quality and high separation yield.
Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
supporting information, p. 12671 - 12674 (2021/12/04)
Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
Hydroboration Reaction and Mechanism of Carboxylic Acids using NaNH2(BH3)2, a Hydroboration Reagent with Reducing Capability between NaBH4and LiAlH4
Wang, Jin,Ju, Ming-Yue,Wang, Xinghua,Ma, Yan-Na,Wei, Donghui,Chen, Xuenian
, p. 5305 - 5316 (2021/04/12)
Hydroboration reactions of carboxylic acids using sodium aminodiboranate (NaNH2[BH3]2, NaADBH) to form primary alcohols were systematically investigated, and the reduction mechanism was elucidated experimentally and computationally. The transfer of hydride ions from B atoms to C atoms, the key step in the mechanism, was theoretically illustrated and supported by experimental results. The intermediates of NH2B2H5, PhCH= CHCOOBH2NH2BH3-, PhCH= CHCH2OBO, and the byproducts of BH4-, NH2BH2, and NH2BH3- were identified and characterized by 11B and 1H NMR. The reducing capacity of NaADBH was found between that of NaBH4 and LiAlH4. We have thus found that NaADBH is a promising reducing agent for hydroboration because of its stability and easy handling. These reactions exhibit excellent yields and good selectivity, therefore providing alternative synthetic approaches for the conversion of carboxylic acids to primary alcohols with a wide range of functional group tolerance.
A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
supporting information, p. 16865 - 16873 (2021/10/20)
Employing a bifunctional catalyst based on a copper(I)/NHC complex and a guanidine organocatalyst, catalytic ester reductions to alcohols with H2 as terminal reducing agent are facilitated. The approach taken here enables the simultaneous activation of esters through hydrogen bonding and formation of nucleophilic copper(I) hydrides from H2, resulting in a catalytic hydride transfer to esters. The reduction step is further facilitated by a proton shuttle mediated by the guanidinium subunit. This bifunctional approach to ester reductions for the first time shifts the reactivity of generally considered "soft"copper(I) hydrides to previously unreactive "hard"ester electrophiles and paves the way for a replacement of stoichiometric reducing agents by a catalyst and H2.
A mild and selective Cu(II) salts-catalyzed reduction of nitro, azo, azoxy, N-aryl hydroxylamine, nitroso, acid halide, ester, and azide compounds using hydrogen surrogacy of sodium borohydride
Kalola, Anirudhdha G.,Prasad, Pratibha,Mokariya, Jaydeep A.,Patel, Manish P.
supporting information, p. 3565 - 3589 (2021/10/12)
The first mild, in situ, single-pot, high-yielding well-screened copper (II) salt-based catalyst system utilizing the hydrogen surrogacy of sodium borohydride for selective hydrogenation of a broad range of nitro substrates into the corresponding amine under habitancy of water or methanol like green solvents have been described. Moreover, this catalytic system can also activate various functional groups for hydride reduction within prompted time, with low catalyst-loading, without any requirement of high pressure or molecular hydrogen supply. Notably, this system explores a great potential to substitute expensive traditional hydrogenation methodologies and thus offers a greener and simple hydrogenative strategy in the field of organic synthesis.
Uranyl(VI) Triflate as Catalyst for the Meerwein-Ponndorf-Verley Reaction
Kobylarski, Marie,Monsigny, Louis,Thuéry, Pierre,Berthet, Jean-Claude,Cantat, Thibault
supporting information, p. 16140 - 16148 (2021/11/01)
Catalytic transformation of oxygenated compounds is challenging in f-element chemistry due to the high oxophilicity of the f-block metals. We report here the first Meerwein-Ponndorf-Verley (MPV) reduction of carbonyl substrates with uranium-based catalysts, in particular from a series of uranyl(VI) compounds where [UO2(OTf)2] (1) displays the greatest efficiency (OTf = trifluoromethanesulfonate). [UO2(OTf)2] reduces a series of aromatic and aliphatic aldehydes and ketones into their corresponding alcohols with moderate to excellent yields, using iPrOH as a solvent and a reductant. The reaction proceeds under mild conditions (80 °C) with an optimized catalytic charge of 2.3 mol % and KOiPr as a cocatalyst. The reduction of aldehydes (1-10 h) is faster than that of ketones (>15 h). NMR investigations clearly evidence the formation of hemiacetal intermediates with aldehydes, while they are not formed with ketones.
Disproportionation of aliphatic and aromatic aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions
Sharifi, Sina,Sharifi, Hannah,Koza, Darrell,Aminkhani, Ali
, p. 803 - 808 (2021/07/20)
Disproportionation of aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions often requires the application of high temperatures, equimolar or excess quantities of strong bases, and is mostly limited to the aldehydes with no CH2 or CH3 adjacent to the carbonyl group. Herein, we developed an efficient, mild, and multifunctional catalytic system consisting AlCl3/Et3N in CH2Cl2, that can selectively convert a wide range of not only aliphatic, but also aromatic aldehydes to the corresponding alcohols, acids, and dimerized esters at room temperature, and in high yields, without formation of the side products that are generally observed. We have also shown that higher AlCl3 content favors the reaction towards Cannizzaro reaction, yet lower content favors Tishchenko reaction. Moreover, the presence of hydride donor alcohols in the reaction mixture completely directs the reaction towards the Meerwein–Ponndorf–Verley reaction. Graphic abstract: [Figure not available: see fulltext.].
