24393-54-2Relevant academic research and scientific papers
Regio- And diastereoselective Pd-catalyzed aminochlorocyclization of allylic carbamates: scope, derivatization, and mechanism
Ariga, Elaine Miho,Carita Correra, Thiago,Matsushima, Jullyane Emi,McIndoe, J. Scott,Moreira Ribeiro, Francisco Wanderson,Omari, Isaac,Papa Spadafora, Bruna,Rodrigues, Alessandro,Soares, Priscila Machado Arruda,Vinhato, Elisangela,de Oliveira-Silva, Diogo
supporting information, p. 5595 - 5606 (2021/07/02)
The regio- and diastereoselective synthesis of oxazolidinonesviaa Pd-catalyzed vicinal C-N/C-Cl bond-forming reaction from internal alkenes of allylic carbamates is reported. The oxazolidinones are obtained in yields of 44 to 95% with high to excellent diastereoselectivities (from 6?:?1 to >20?:?1 dr) from readily available precursors. This process is scalable, and the products are suitable for the synthesis of useful amino alcohols. A detailed theoretical and experimental mechanistic study was carried out to describe that the reaction proceeds through ananti-aminopalladation of the alkene followed by an oxidative C-Pd(ii) cleavage with retention of the carbon stereochemistry to yield the major diastereomer. The role of Cu(ii) in a C-Cl bond-forming mechanism step has also been proposed.
Solvent role in the lipase-catalysed esterification of cinnamic acid and derivatives. Optimisation of the biotransformation conditions
Suárez-Escobedo, Laura,Gotor-Fernández, Vicente
, (2021/02/05)
The esterification of cinnamic acid has been deeply investigated using ethanol as nucleophile and Candida antarctica lipase type B (CAL-B) as suitable biocatalyst. Special attention has been paid to the role that the solvent plays in the production of ethyl cinnamate. Therefore, volatile organic solvents and deep eutectic mixtures were employed in order to find optimal reaction conditions. Once that hexane was selected as the solvent of choice, other parameters that affect the enzyme activity were investigated in order to produce ethyl cinnamate with excellent yield. The CAL-B loading, nucleophile equivalents, temperature and reaction time have been identified as key parameters in the enzyme efficiency, and the potential of lipase-catalysed esterification has been finally exploited to produce a series of ethyl esters with different pattern substitutions on the aromatic ring.
Hypervalent iodine(iii) induced oxidative olefination of benzylamines using Wittig reagents
Ramavath, Vijayalakshmi,Rupanawar, Bapurao D.,More, Satish G.,Bansode, Ajay H.,Suryavanshi, Gurunath
, p. 8806 - 8813 (2021/05/26)
We have developed hypervalent iodine(iii) induced oxidative olefination of primary and secondary benzylamines using 2C-Wittig reagents, which provides easy access to α,β-unsaturated esters. Mild reaction conditions, good to excellent yields with high (E) selectivity, and a broad substrate scope are the key features of this reaction. We have successfully carried out the gram-scale synthesis of α,β-unsaturated esters.
Selective Synthesis of Z-Cinnamyl Ethers and Cinnamyl Alcohols through Visible Light-Promoted Photocatalytic E to Z Isomerization
Li, Hengchao,Chen, Hang,Zhou, Yang,Huang, Jin,Yi, Jundan,Zhao, Hongcai,Wang, Wei,Jing, Linhai
supporting information, p. 555 - 559 (2020/02/05)
A photocatalytic E to Z isomerization of alkenes using an iridium photosensitizer under mild reaction conditions is disclosed. This method provides scalable and efficient access to Z-cinnamyl ether and allylic alcohol derivatives in high yields with excellent stereoselectivity. Importantly, this method also provides a powerful strategy for the selective synthesis of Z-magnolol and honokiol derivatives possessing potential biological activity.
Dual ligand-promoted palladium-catalyzed nondirected C-H alkenylation of aryl ethers
Fu, Manlin,Liu, Jiang,Wang, Lei,Yin, Biao,Zhu, Qing
supporting information, p. 3293 - 3296 (2020/04/02)
Direct C-H functionalization of aryl ethers remains challenging owing to their low reactivity and selectivity. Herein, a novel strategy for nondirected C-H alkenylation of aryl ethers promoted by a dual ligand catalyst was demonstrated. This catalytic system readily achieved the highly efficient alkenylation of alkyl aryl ethers (anisole, phenetole, n-propyl phenyl ether, n-butyl phenyl ether and benzyl phenyl ether), cyclic aryl ethers (1,4-benzodioxan, 2,3-dihydrobenzofuran, dibenzofuran), and diphenyl oxides. Moreover, the proposed methodology was successfully employed for the late-stage modification of complex drugs containing the aryl ether motif. Interestingly, the compounds developed herein displayed fluorescent properties, which would facilitate their biological applications.
Highly active homoleptic nickel(II) bis-N-heterocyclic carbene catalyst for Suzuki–Miyaura and Heck cross-coupling reactions
Nirmala, Muthukumaran,Arruri, Sathyanarayana,Vaddamanu, Moulali,Karupnaswamy, Ramesh,Mannarsamy, Maruthupandi,Adinarayana, Mannem,Ganesan, Prabusankar
supporting information, p. 125 - 134 (2018/11/23)
New homoleptic nickel(II) biscarbene complex was synthesized and structurally characterized. The complex depicted the excellent catalytic activities with only 3 mol% catalyst loading along with wide substrate scope for the Suzuki–Miyaura cross-coupling reactions (twenty six examples) and Heck coupling reactions (eighteen examples).
Bis(pyrazolyl)palladium(II) complexes as catalysts for Mizoroki–Heck cross-coupling reactions
Ocansey, Edward,Darkwa, James,Makhubela, Banothile C.E.
, p. 52 - 59 (2019/04/10)
Recent progress in carbon–carbon cross-coupling reactions has resulted in the discovery of highly active catalysts for carrying out such transformations. However, due to the wide array of applications of the products from cross-coupling reactions, there is the need to design suitable catalysts that permit the practical and economical synthesis of the cross-coupled products. Palladium complexes with bulky and electron-donating ligands have served as excellent (pre)catalysts for the Mizoroki–Heck cross-coupling reaction. By using bulky pyrazole-based ligands, we have prepared palladium(II) complexes with controlled steric and electronic properties of the metal center. We have used these bulky bis(pyrazolyl)palladium(II) complexes as (pre)catalysts for the Mizoroki–Heck cross-coupling reaction. The (pre)catalysts displayed high activity and selectivity, giving high catalytic conversions at a low (pre)catalyst loading and short reaction times. A mercury poisoning test confirmed that the (pre)catalysts promoted the Mizoroki–Heck cross-coupling homogenously and do not decompose into palladium black during the reactions. The catalytic systems were also tolerant to the presence of functional groups, such as 4-CF3, 4-CH3, 4-CO2Me and 4-CO2Et, on the alkene substrates.
Rh-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to 3-Arylpropenoates: Enantioselective Synthesis of (R)-Tolterodine
Zullo, Valerio,Iuliano, Anna
supporting information, p. 1377 - 1384 (2019/01/04)
A highly enantioselective conjugate addition of arylboronic acids to 3-arylpropenoates is presented. The rhodium complexes obtained from deoxycholic acid derived binaphthyl phosphites showed good activity as well as very high enantioselectivity (ee up to 99 %) in the conjugate addition to different ethyl-3-arylpropenoates, allowing to obtain useful chiral building blocks for the synthesis of active pharmaceutical ingredients. The method was applied to the enantioselective synthesis of the antimuscarinic drug (R)-tolterodine.
Rh(III)-Catalyzed Enaminone-Directed C-H Coupling with α-Diazo-α-phosphonoacetate for Reactivity Discovery: Fluoride-Mediated Dephosphonation for C-C Coupling Reactions
Song, Chao,Yang, Chen,Zeng, Hua,Zhang, Wenjing,Guo, Shan,Zhu, Jin
supporting information, p. 3819 - 3823 (2018/07/22)
Rh(III)-catalyzed enaminone-directed C-H coupling with α-diazo-α-phosphonoacetate has been used for the identification of fluoride-mediated dephosphonation C-C coupling reactivity for the synthesis of 4-hydroxy-1-naphthoates. Intermolecular C-C coupling of α-phosphonoacetate and benzaldehyde for (E)-selective α,β-unsaturated ester synthesis has also been achieved.
One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
, p. 107 - 118 (2017/09/28)
A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
