22767-95-9Relevant academic research and scientific papers
Esterification or Thioesterification of Carboxylic Acids with Alcohols or Thiols Using Amphipathic Monolith-SO3H Resin
Ichihara, Shuta,Ishida, Moeka,Ito, Ryo,Kato, Ayumu,Monguchi, Yasunari,Nakamura, Shinji,Park, Kwihwan,Sajiki, Hironao,Takada, Hitoshi,Wakayama, Fumika,Yamada, Tsuyoshi,Yamada, Yutaro
, p. 2702 - 2710 (2022/01/19)
We have developed a method for the esterification of carboxylic acids with alcohols using amphipathic, monolithic-resin bearing sulfonic acid moieties as cation exchange functions (monolith-SO3H). Monolith-SO3H efficiently catalyzed the esterification of aromatic and aliphatic carboxylic acids with various primary and secondary alcohols (1.55.0 equiv) in toluene at 6080 °C without the need to remove water generated during the reaction. The amphipathic property of monolith-SO3H facilitates dehydration due to its capacity for water absorption. This reaction was also applicable to thioesterification, wherein the corresponding thioesters were obtained in excellent yield using only 2.0 equiv of thiol in toluene, although heating at 120 °C was required. Moreover, monolith-SO3H was separable from the reaction mixtures by simple filtration and reused for at least five runs without decreasing the catalytic activity.
Manganese-catalyzed homogeneous hydrogenation of ketones and conjugate reduction of α,β-unsaturated carboxylic acid derivatives: A chemoselective, robust, and phosphine-free in situ-protocol
Topf, Christoph,Vielhaber, Thomas
, (2021/07/10)
We communicate a user-friendly and glove-box-free catalytic protocol for the manganese-catalyzed hydrogenation of ketones and conjugated C[dbnd]C[sbnd]bonds of esters and nitriles. The respective catalyst is readily assembled in situ from the privileged [Mn(CO)5Br] precursor and cheap 2-picolylamine. The catalytic transformations were performed in the presence of t-BuOK whereby the corresponding hydrogenation products were obtained in good to excellent yields. The described system offers a brisk and atom-efficient access to both secondary alcohols and saturated esters avoiding the use of oxygen-sensitive and expensive phosphine-based ligands.
Chemoselective reduction of ?,￠-unsaturated carbonyl and carboxylic compounds by hydrogen iodide
Matsumoto, Shoji,Marumoto, Hayato,Akazome, Motohiro,Otani, Yasuhiko,Kaiho, Tatsuo
, p. 590 - 599 (2021/03/29)
The selective reduction of ?,￠-unsaturated carbonyl compounds was achieved to produce saturated carbonyl compounds with aqueous HI solution. The introduction of an aryl group at an ? or ￠ position efficiently facilitated the reduction with good yield. The reaction was applicable to compounds bearing carboxylic acids and halogen atoms. Through the investigation of the reaction mechanism, it was found that Michael-type addition of iodide occurred to produce ￠-iodo compounds followed by the reduction of C-I bond via anionic and radical paths.
Method for preparing organic carboxylic ester through combined catalysis of aryl bidentate phosphine ligand
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Paragraph 0051, (2020/05/29)
The invention discloses a method for preparing organic carboxylic ester by combined catalysis of an aryl bidentate phosphine ligand. The method comprises the following steps: under the action of a palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, carrying out a hydrogen esterification reaction on terminal olefin, carbon monoxide and alcohol so as to generate theorganic carboxylic ester with one more carbon than olefin. According to the invention, by adoption of the palladium compound/aryl bidentate phosphine ligand/acidic additive combined catalyst, good catalytic activity and selectivity for the hydrogen esterification reaction of the olefin are achieved, and olefin carbonylation to synthesize organic carboxylic ester can be efficiently catalyzed. Thearyl bidentate phosphine ligand has a rigid skeleton structure of a rigid ligand and the flexibility of a flexible ligand, so the aryl bidentate phosphine ligand has proper flexibility due to the characteristic that the aryl bidentate phosphine ligand is soft and rigid, and a most favorable coordination mode and a stable active structure in space are favorably formed. In addition, the aryl bidentate phosphine ligand has the advantages of high stability, simple and convenient synthesis method and the like; and a novel industrial technology is provided for production of organic carboxylate compounds.
Direct Catalytic Alcoholysis of Unactivated 8-Aminoquinoline Amides
Deguchi, Toru,Xin, Hai-Long,Morimoto, Hiroyuki,Ohshima, Takashi
, p. 3157 - 3161 (2017/06/09)
Direct catalytic alcoholysis of unactivated amides is one of the most difficult challenges in organic chemistry, and an applicable method for cleaving amides used as directing groups in regioselective functionalization reactions has not been reported. Herein, we report direct catalytic alcoholysis of 8-aminoquinoline amides, which are highly effective directing groups in regioselective functionalization reactions. The reactions proceeded with a simple combination of substrates, air-stable catalysts, and alcohols, affording the corresponding esters in good yields with broad functional group tolerance. Highly chemoselective cleavage of the 8-aminoquinoline amides in the presence of related carbonyl functionalities and preliminary mechanistic studies are also described.
Esterification, transesterification and hydrogenation reactions of polyunsaturated compounds catalyzed by a recyclable polymer supported palladium catalyst
Dell'Anna, Maria Michela,Capodiferro, Vito Filippo,Mali, Matilda,Mastrorilli, Piero
, p. 106 - 114 (2016/07/06)
Aliphatic and aromatic carboxylic acids were converted into their corresponding esters using a polymer supported palladium(II) β-ketoesterate complex under hydrogen atmosphere in the presence of catalytic bromobenzene in alcohols. This method was also applicable to the transesterification of esters. Good to excellent yields were obtained for different aliphatic or aromatic starting materials. The esterification (or transesterification) was promoted by the in situ generation of HBr from bromobenzene, which provided a mild acidic reaction environment. Pd(II) centers were converted into polymer stabilized metal nanoparticles (the true active species) under reaction conditions. The palladium catalyst exhibited a remarkable activity and was reusable for eight consecutive cycles. The present system was also tested for the preparation of partially hydrogenated fatty acid methyl esters, starting from a mixture composed by highly polyunsaturated esters and free carboxylic acids, taken as a model acidic feedstock for biodiesel upgrading.
A green approach for the decoration of Pd nanoparticles on graphene nanosheets: An in situ process for the reduction of C-C double bonds and a reusable catalyst for the Suzuki cross-coupling reaction
Hussain, Najrul,Borah, Ashwini,Darabdhara, Gitashree,Gogoi, Pranjal,Azhagan, Vedi Kuyil,Shelke, Manjusha V.,Das, Manash R.
, p. 6631 - 6641 (2015/08/06)
A new strategy for in situ synthesis of palladium nanoparticles (Pd NPs) decorated on reduced graphene oxide (rGO) nanosheets with controlled size and shape is reported. This strategy was designed as three processes in one pot, namely, (a) reduction of graphene oxide, (b) formation of Pd NPs on the rGO nanosheets and (c) simultaneous reduction of olefin. In this synthesis process, a hydrogen atmosphere was used to develop the Pd NPs-rGO nanocatalyst, which is reusable and easily separable. The influence of the size and morphology of the Pd-rGO-H2 catalyst on the catalytic activity in the Suzuki cross-coupling reaction was investigated by comparing with other catalysts, Pd-rGO-As and Pd-rGO-Gl, and they were synthesized by different reducing agents, ascorbic acid and glucose, respectively. The catalysts were characterized by electron microscopy (HRTEM, SEM), FT-IR, XRD and XPS. The Pd-rGO-H2 catalyst was found to possess excellent catalytic activity and recyclability in the Suzuki cross-coupling reaction under mild reaction conditions.
Ambulation of Incipient Proton during Gas-Phase Dissociation of Protonated Alkyl Dihydrocinnamates
Xu, Sihang,Zhang, Yong,Errabelli, Ramu,Attygalle, Athula B.
, p. 9468 - 9479 (2015/10/12)
Upon activation in the gas phase, protonated alkyl dihydrocinnamates undergo an alcohol loss. However, the mechanism followed is not a simple removal of an alkanol molecule after a protonation on the alkoxy group. The mass spectrum of the m/z 166 ion for deuteron-charged methyl dihydrocinnamate showed two peaks of 1:5 intensity ratio at m/z 133 and 134 to confirm that the incipient proton is mobile. The proton initially attached to the carbonyl group migrates to the ring and randomizes before a subsequent transfer of one of the ring protons to the alkoxy group for the concomitant alcohol elimination. Moreover, protonated methyl dihydrocinnamate undergoes more than one H/D exchange. The spectra recorded from m/z 167 and 168 ions obtained for di- and tri-deuterio isotopologues showed peak pairs at m/z 134, 135 and 135, 136, at 1:2 and 1:1 intensity ratios, respectively, confirming the benzenium ion intermediate achieves complete randomization before the proton transfer. Additionally, protonated higher esters of alkyl dihydrocinnamates undergo a cleavage of the O-CH2 bond to form an ion/neutral complex, which, upon activation, dissociates generating a carbenium ion and dihydrocinnamic acid, or rearranges to generate protonated dihydrocinnamic acid and an alkene by a nonspecific proton transfer.
A recyclable CO surrogate in regioselective alkoxycarbonylation of alkenes: Indirect use of carbon dioxide
Gehrtz,Hirschbeck,Fleischer
supporting information, p. 12574 - 12577 (2015/08/06)
Herein, we report a Pd-catalysed alkoxycarbonylation of alkenes based on the use of a recyclable CO2 reduction product, the crystalline and air-stable N-formylsaccharin, as a CO surrogate. The carbonylation proceeds under ambient conditions in an exceptionally complementary regioselective fashion yielding the desired branched products from styrene derivatives and valuable linear esters from alkyl-substituted alkenes.
LED lighting as a simple, inexpensive, and sustainable alternative for Wolff rearrangements
Bernardim, Barbara,Hardman-Baldwin, Andrea M.,Burtoloso, Antonio C. B.
, p. 13311 - 13314 (2015/02/19)
The Wolff rearrangement is one of the best methods for chain homologation. However, it still suffers from many drawbacks with respect to its practical execution in the laboratory. We wish to demonstrate the use of commercial LED lamps as a sustainable alternative for the classic experimental protocols typically used for Wolff rearrangements. This journal is
