4410-31-5Relevant articles and documents
Hydration of Cyanohydrins by Highly Active Cationic Pt Catalysts: Mechanism and Scope
Li, Chengcheng,Chang, Xiao-Yong,Huo, Luqiong,Tan, Haibo,Xing, Xiangyou,Xu, Chen
, p. 8716 - 8726 (2021/07/26)
Cyanohydrins (α-hydroxy nitriles) are a special type of nitriles that readily decompose into hydrogen cyanide (HCN) and the corresponding carbonyl compounds. Hydration of cyanohydrins that are readily available through cyanation of aldehydes and ketones provides the most straightforward route to valuable α-hydroxyamides. However, due to low stability of cyanohydrins and deactivation of the catalysts by the released HCN, catalytic direct hydration of cyanohydrins still remains largely unsolved. As a general trend, cyanohydrins containing bulkier substituents, such as α,α-diaryl cyanohydrins, degrade more quickly and thus are more difficult to be hydrated. Here, we report development of cationic platinum catalysts that exhibit high reactivity for hydration of various cyanohydrins. Detailed mechanistic investigations for hydration of nitriles by (PμP)Pt(PR2OH)X(OTf) reveal a catalytic cycle involving the formation of a five-membered metallacyclic intermediate and subsequent hydrolysis via attacking on the phosphorus of the secondary phosphine oxide (PR2OH) ligand by H2O. We discovered that Pt catalyst A bearing the electron-rich, appropriately small-bite-angle bisphosphine ligand provides super reactivity for hydration of cyanohydrins. The hydration reactions catalyzed by A proceed at ambient temperatures and occur with a wide variety of cyanohydrins, including the most difficult α,α-diaryl cyanohydrins, with good turnover numbers.
Catalyst, preparation method thereof and preparation method of amide compound
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Paragraph 0142-0146; 0147, (2020/01/12)
The invention relates to a catalyst, a preparation method thereof, and a preparation method for hydrating nitrile groups into amides. The catalyst is used for catalyzing nitrile groups to be hydratedinto amides, and the structural general formula of the catalyst is shown in the specification. In the formula, a plurality of R are respectively and independently ones selected from aromatic groups, heteroaromatic groups and non-aromatic ring groups; a plurality of R are ones respectively and independently selected from linear alkyl groups and alkane aromatic groups; X is one selected from Cl and Br; and L is one selected from OTf, BF4, PF6 and SbF6. The catalyst can catalyze nitrile groups to be hydrated into amides, and the nitrile groups can be catalyzed to be hydrated into amides even at a low temperature (20-80 DEG C); besides, compared with existing common catalysts for catalyzing nitrile groups to be hydrated into amides, the catalyst has the advantages that the equivalent weight of the catalyst can be obviously reduced, and nitrile groups can reach a relatively high conversion rate when the equivalent weight of the catalyst is only 0.01 mol%-0.5 mol%; and meanwhile, the catalyst is wider in application range and can catalyze various nitrile compounds to be hydrated into amide compounds.
One-pot method for the synthesis of 1-aryl-2-aminoalkanol derivatives from the corresponding amides or nitriles
Bobal, Pavel,Otevrel, Jan,Svestka, David
, p. 25029 - 25045 (2020/07/14)
We have identified a novel one-pot method for the synthesis of β-amino alcohols, which is based on C-H bond hydroxylation at the benzylic α-carbon atom with a subsequent nitrile or amide functional group reduction. This cascade process uses molecular oxygen as an oxidant and sodium bis(2-methoxyethoxy)aluminum hydride as a reductant. The substrate scope was examined on 30 entries and, although the respective products were provided in moderate yields only, the above simple protocol may serve as a direct and powerful entry to the sterically congested 1,2-amino alcohols that are difficult to prepare by other routes. The plausible mechanistic rationale for the observed results is given and the reaction was applied to a synthesis of a potentially bioactive target. This journal is
Catalytic Transfer Hydration of Cyanohydrins to α-Hydroxyamides
Kanda, Tomoya,Naraoka, Asuka,Naka, Hiroshi
supporting information, p. 825 - 830 (2019/01/14)
We report the palladium(II)-catalyzed transfer hydration of cyanohydrins to α-hydroxyamides by using carboxamides as water donors. This method enables selective hydration of various aldehyde- and ketone-derived cyanohydrins to afford α-mono- and α,α-disubstituted-α-hydroxyamides, respectively, under mild conditions (50 °C, 10 min). The direct conversion of fenofibrate, a drug bearing a benzophenone moiety, into a functionalized α,α-diaryl-α-hydroxyamide was achieved by means of a hydrocyanation-transfer hydration sequence. Preliminary kinetic studies and the synthesis of a site-specifically 18O-labeled α-hydroxyamide demonstrated the carbonyl oxygen transfer from the carboxamide reagent into the α-hydroxyamide product.
Bifunctional organometallic catalysts for selective hydration of nitriles to amides
Singh, Kuldeep,Sarbajna, Abir,Bera, Jitendra K.
, p. 853 - 861 (2020/06/26)
In this report, we highlight our recent contributions towards the development of bifunctional catalysts for selective hydration of nitriles to amides.
Highly Active Platinum Catalysts for Nitrile and Cyanohydrin Hydration: Catalyst Design and Ligand Screening via High-Throughput Techniques
Xing, Xiangyou,Xu, Chen,Chen, Bo,Li, Chengcheng,Virgil, Scott C.,Grubbs, Robert H.
supporting information, p. 17782 - 17789 (2019/01/04)
Nitrile hydration provides access to amides that are indispensable to researchers in chemical and pharmaceutical industries. Prohibiting the use of this venerable reaction, however, are (1) the dearth of biphasic catalysts that can effectively hydrate nitriles at ambient temperatures with high turnover numbers and (2) the unsolved challenge of hydrating cyanohydrins. Herein, we report the design of new "donor-acceptor"-type platinum catalysts by precisely arranging electron-rich and electron-deficient ligands trans to one other, thereby enhancing both the nucleophilicity of the hydroxyl group and the electrophilicity of the nitrile group. Leveraging a high-throughput, automated workflow and evaluating a library of bidentate ligands, we have discovered that commercially available, inexpensive DPPF [1,1′-ferrocenendiyl-bis(diphenylphosphine)] provides superior reactivity. The corresponding "donor-acceptor"-type catalyst 2a is readily prepared from (DPPF)PtCl2, PMe2OH, and AgOTf. The enhanced activity of 2a permits the hydration of a wide range of nitriles and cyanohydrins to proceed at 40 °C with excellent turnover numbers. Rational reevaluation of the ligand structure has led to the discovery of modified catalyst 2c, harboring the more electron-rich 1,1′-bis[bis(5-methyl-2-furanyl)phosphino] ferrocene ligand, which demonstrates the highest activity toward hydration of nitriles and cyanohydrins at room temperature. Finally, the correlation between the electron-donating ability of the phosphine ligands with catalyst efficiencies of 2a, 2c, 2d, and 2e in the hydration of nitrile 7 are examined, and the results support the "donor-acceptor" hypothesis.
Mild and efficient enantioselective synthesis of all stereoisomers of cordiarimide B and their antioxidant study
Jeevan,Umashankara,Kumar, Y.C. Sunil,Kumara,Rangappa
, p. 927 - 932 (2018/03/13)
Four isomers of cordiarimide B were synthesized by coupling (S)-2-amino-1-phenylethanol and (R)-2-amino-1-phenylethanol with L and D glutamic acid. Biological studies revealed that two isomers showed potent antioxidant activity. Among these two, the most
α-ZrP/Uracil/Cu2+ nanoparticles as an efficient catalyst in the Morita-Baylis-Hillman reaction
Hajipour, Abdol R.,Zakery, Saedeh
, (2018/09/06)
A facile synthesis of uracil-Cu2+ nanoparticles immobilized on alpha-zirconium hydrogen phosphate (α-ZrP), abbreviated as α-ZrP/Uracil/Cu2+, was presented. This compound was synthesized by the thermal method and used as a reusable ca
SUBSTITUTED PYRIDINES AS INHIBITORS OF DNMT1
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Page/Page column 536, (2018/01/20)
The invention is directed to substituted pyridine derivatives. Specifically, the invention is directed to compounds according to Formula (Iar): (Iar) wherein Yar, X1ar, X2ar, R1ar, R2ar, R3ar, R4ar and R5ar are as defined herein; or a pharmaceutically acceptable salt or prodrug thereof. The compounds of the invention are selective inhibitors of DNMT1 and can be useful in the treatment of cancer, pre-cancerous syndromes, beta hemoglobinopathy disorders, sickle cell disease, sickle cell anemia, and beta thalassemia, and diseases associated with DNMT1 inhibition. Accordingly, the invention is further directed to pharmaceutical compositions comprising a compound of the invention. The invention is still further directed to methods of inhibiting DNMT1 activity and treatment of disorders associated therewith using a compound of the invention or a pharmaceutical composition comprising a compound of the invention.
Hemilability-Driven Water Activation: A NiII Catalyst for Base-Free Hydration of Nitriles to Amides
Singh, Kuldeep,Sarbajna, Abir,Dutta, Indranil,Pandey, Pragati,Bera, Jitendra K.
, p. 7761 - 7771 (2017/06/06)
The NiII complex 1 containing pyridyl- and hydroxy-functionalized N-heterocyclic carbenes (NHCs) is synthesized and its catalytic utility for the selective nitrile hydration to the corresponding amide under base-free conditions is evaluated. The title compound exploits a hemilabile pyridyl unit to interact with a catalytically relevant water molecule through hydrogen-bonding and promotes a nucleophilic water attack to the nitrile. A wide variety of nitriles is hydrated to the corresponding amides including the pharmaceutical drugs rufinamide, Rifater, and piracetam. Synthetically challenging α-hydroxyamides are accessed from cyanohydrins under neutral conditions. Related catalysts that lack the pyridyl unit (i.e., compounds 2 and 4) are not active whereas those containing both the pyridyl and the hydroxy or only the pyridyl pendant (i.e., compounds 1 and 3) show substantial activity. The linkage isomer 1′ where the hydroxy group is bound to the metal instead of the pyridyl group was isolated under different crystallization conditions insinuating a ligand hemilabile behavior. Additional pKa measurements reveal an accessible pyridyl unit under the catalytic conditions. Kinetic studies support a ligand-promoted nucleophilic water addition to a metal-bound nitrile group. This work reports a Ni-based catalyst that exhibits functional hemilability for hydration chemistry.
