- CARBON-13 SUBSTITUENT CHEMICAL SHIFTS IN THE SIDE-CHAIN CARBONS OF AROMATIC SYSTEMS: THE IMPORTANCE OF Π-POLARIZATION IN DETERMINING CHEMICAL SHIFTS
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13C substituent chemical shifts of the carbonyl sites in the side-chains of meta- and para-substituted benzenes of the type XC6H4COZ have been measured.Analysis of this data using the dual substituent parameter method shows that inductive effeccts are predominant.The reverse inductive contribution observed is explained in therms of a Π-polarization mechanism.Critical support for this mechanism is obtained from additional series where the carbonyl is complexed with Lewis acids.The concepts of 'extended' and 'localized' Π-polarization are discussed.
- Bromilow, John,Brownlee, Robert T. C.,Craik, David J.,Fiske, Peter R.,Rowe, Jeffrey E.,Sadek, Maruse
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- Design, Synthesis, and Study of the Insecticidal Activity of Novel Steroidal 1,3,4-Oxadiazoles
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A series of novel steroidal derivatives with a substituted 1,3,4-oxadiazole structure was designed and synthesized, and the target compounds were evaluated for their insecticidal activity against five aphid species. Most of the tested compounds exhibited potent insecticidal activity against Eriosoma lanigerum (Hausmann), Myzus persicae, and Aphis citricola. Compounds 20g and 24g displayed the highest activity against E. lanigerum, showing LC50 values of 27.6 and 30.4 μg/mL, respectively. Ultrastructural changes in the midgut cells of E. lanigerum were detected by transmission electron microscopy, indicating that these steroidal oxazole derivatives might exert their insecticidal activity by destroying the mitochondria and nuclear membranes in insect midgut cells. Furthermore, a field trial showed that compound 20g exhibited effects similar to those of the positive controls chlorpyrifos and thiamethoxam against E. lanigerum, reaching a control rate of 89.5% at a dose of 200 μg/mL after 21 days. We also investigated the hydrolysis and metabolism of the target compounds in E. lanigerum by assaying the activities of three insecticide-detoxifying enzymes. Compound 20g at 50 μg/mL exhibited inhibitory action on carboxylesterase similar to the known inhibitor triphenyl phosphate. The above results demonstrate the potential of these steroidal oxazole derivatives to be developed as novel pesticides.
- Bai, Hangyu,Jiang, Weiqi,Li, Qi,Li, Tian,Ma, Shichuang,Shi, Baojun,Wu, Wenjun
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p. 11572 - 11581
(2021/10/12)
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- A Bifunctional Copper Catalyst Enables Ester Reduction with H2: Expanding the Reactivity Space of Nucleophilic Copper Hydrides
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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.
- Kaicharla, Trinadh,Ngoc, Trung Tran,Teichert, Johannes F.,Tzaras, Dimitrios-Ioannis,Zimmermann, Birte M.
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supporting information
p. 16865 - 16873
(2021/10/20)
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- Copper-mediated simple and direct aerobic oxidative esterification of arylacetonitriles with alcohols/phenols
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A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C-H bond, cleavage of inert C-C bond, and formation of C-O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
- Dong, Jianyu,Chen, Xiuling,Ji, Fangyan,Liu, Lixin,Su, Lebin,Mo, Min,Tang, Jian-Sheng,Zhou, Yongbo
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- Pleuromutilin derivative with 1, 3, 4-oxadiazole side chain and preparation and application thereof
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The invention belongs to the field of medicinal chemistry, and particularly relates to a pleuromutilin derivative with a 1, 3, 4-oxadiazole side chain and preparation and application thereof The pleuromutilin derivative with the 1, 3, 4-oxadiazole side chain is a compound shown in a formula 2 or a pharmaceutically acceptable salt thereof, and a solvent compound, an enantiomer, a diastereoisomer and a tautomer of the compound shown in the formula 2 or the pharmaceutically acceptable salt thereof or a mixture of the solvent compound, the enantiomer, the diastereoisomer and the tautomer in any proportion, including a racemic mixture. The pleuromutilin derivative has good antibacterial activity, is especially suitable for being used as a novel antibacterial agent for systemic system infection of animals or human beings, and has good water solubility.
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Paragraph 0055-0056; 0070; 0090; 0092; 0095; 0103
(2021/07/24)
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- Synthesis and bioactivity of sulfide derivatives containing 1,3,4-oxadiazole and pyridine
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A series of novel sulfide derivatives containing 1,3,4-oxadiazole and pyridine were synthesized, characterized, and tested for their antibacterial activity against tobacco bacterial wilt and rice bacterial blight and for insecticidal activity toward diamondback moth. The results showed that some compounds had good insecticidal and bactericidal activity, e.g., the activities of compounds 6e and 6g–6j toward tobacco bacterial wilt were much better than those of commercial thiodiazole-copper, and some of the synthesized compounds possessed good insecticidal activity against Plutella xylostella. Compounds 6d, 6h, 6j, 6l, 6p, 6r, and 6p displayed over 93% activity at 500 mg L? 1.
- Yu, Gang,Chen, Shunhong,He, Feng,Luo, Dexia,Zhang, Yu,Wu, Jian
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p. 1075 - 1085
(2019/09/10)
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- Design, synthesis, insecticidal activity and 3D-QSR study for novel trifluoromethyl pyridine derivatives containing an 1,3,4-oxadiazole moiety
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A series of trifluoromethyl pyridine derivatives containing 1,3,4-oxadiazole moiety was designed, synthesized and bio-assayed for their insecticidal activity. The result of bio-assays indicated the synthesized compounds exhibited good insecticidal activity against Mythimna separata and Plutella xylostella, most of the title compounds show 100% insecticidal activity at 500 mg L-1 and >80% activity at 250 mg L-1 against the two pests. Compounds E18 and E27 showed LC50 values of 38.5 and 30.8 mg L-1 against Mythimna separata, respectively, which were close to that of avermectin (29.6 mg L-1); compounds E5, E6, E9, E10, E15, E25, E26, and E27 showed 100% activity at 250 mg L-1, which were better than chlorpyrifos (87%). CoMFA and CoMSIA models with good predictability were proposed, which revealed the electron-withdrawing groups with an appropriate bulk at 2- and 4-positions of benzene ring could enhance insecticidal activity.
- Xu,Wang,Luo,Yu,Guo,Fu,Zhao,Wu
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p. 6306 - 6314
(2018/02/19)
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- Facile, highly efficient and environmentally friendly transesterification mediated by platinum dioxide and nickel oxide under essentially neutral conditions
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A practical, facile and highly efficient transesterification reaction under essentially neutral conditions was achieved using platinum dioxide (PtO2) or PtO2/nickel oxide (NiO) as the catalyst. A number of esters and alcohols that contain various functional groups were employed. Good to excellent yields were obtained for different aromatic or aliphatic starting materials. The Pt-alcohol intermediate generated in situ facilitated the exchange of low-alcohol esters to high-alcohol esters.
- Teng, Binhao,Shi, Jiangong,Yao, Chunsuo
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supporting information
p. 2465 - 2471
(2018/06/11)
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- Synthesis and biological activities of cyclanone O-(2-(3-aryl-4- amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives
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Twelve cyclanone O-(2-(3-aryl-4-amino-4H-1,2,4-triazol-3-yl)thio)acetyl)oxime derivatives were synthesized and their structures were confirmed by spectroscopy (IR, 1H NMR, 13C NMR, 19F NMR) and elemental analysis. Their antifungal and antibacterial activities were evaluated against six fungi (Gibberella zeae, Fusarium oxysporum, Clematis mandshurica, Phytophthora infestans, Paralepetopsis sasakii, Sclerotinia sclerotiorum) and two bacteria (Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas citri subsp. Citri (Xcc)). The results indicated that most of the title compounds exhibited good antibacterial activities. Among them, compounds 6d, 6g, 6h, and 6j showed better antibacterial activities against Xoo and Xcc than that of the commercial agent thiodiazole-copper.
- Chen, Meihang,Chen, Lijuan,Zhu, Xuesong,Wang, Xiaobin,Li, Qin,Zhang, Juping,Lu, Daowang,Xue, Wei
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p. 1259 - 1263
(2017/10/18)
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- SO2F2-Mediated One-Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd-Catalyzed Insertion of Carbon Monoxide
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A one-pot Pd-catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.
- Fang, Wan-Yin,Leng, Jing,Qin, Hua-Li
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supporting information
p. 2323 - 2331
(2017/09/06)
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- Stoichiometric and Catalytic Aryl-Perfluoroalkyl Coupling at Tri-tert-butylphosphine Palladium(II) Complexes
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This Communication describes studies of Ph-RF (RF = CF3 or CF2CF3) coupling at Pd complexes of general structure (PtBu3)PdII(Ph)(RF). The CF3 analogue participates in fast Ph-CF3 coupling (II complex. Furthermore, they show that this undesired pathway can be circumvented by changing from a CF3 to a CF2CF3 ligand. Ultimately, the insights gained from stoichiometric studies enabled the identification of Pd(PtBu3)2 as a catalyst for the Pd-catalyzed cross-coupling of aryl bromides with TMSCF2CF3 to afford pentafluoroethylated arenes.
- Ferguson, Devin M.,Bour, James R.,Canty, Allan J.,Kampf, Jeff W.,Sanford, Melanie S.
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supporting information
p. 11662 - 11665
(2017/09/07)
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- Practical: In situ -generation of phosphinite ligands for palladium-catalyzed carbonylation of (hetero)aryl bromides forming esters
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An effective method for alkoxycarbonylation of (hetero)aryl bromides is developed in the presence of in situ-generated phosphinite ligands tBu2POR (R = nBu, nPr, Et or Me). For this purpose commercially available tBu2PCl was used as the pre-ligand in the presence of different alcohols. For the first time cross coupling reactions with two alcohols-one generating the ligand, the other used as substrate-were developed. Through this method, ligand optimization can be performed in a more efficient manner and the desired products could be obtained with good yields and selectivity.
- Wang, Lin,Neumann, Helfried,Spannenberg, Anke,Beller, Matthias
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supporting information
p. 7469 - 7472
(2017/07/12)
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- Addressing the Glycine-Rich Loop of Protein Kinases by a Multi-Facetted Interaction Network: Inhibition of PKA and a PKB Mimic
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Protein kinases continue to be hot targets in drug discovery research, as they are involved in many essential cellular processes and their deregulation can lead to a variety of diseases. A series of 32 enantiomerically pure inhibitors was synthesized and tested towards protein kinase A (PKA) and protein kinase B mimic PKAB3 (PKA triple mutant). The ligands bind to the hinge region, ribose pocket, and glycine-rich loop at the ATP site. Biological assays showed high potency against PKA, with Ki values in the low nanomolar range. The investigation demonstrates the significance of targeting the often neglected glycine-rich loop for gaining high binding potency. X-ray co-crystal structures revealed a multi-facetted network of ligand-loop interactions for the tightest binders, involving orthogonal dipolar contacts, sulfur and other dispersive contacts, amide-π stacking, and H-bonding to organofluorine, besides efficient water replacement. The network was analyzed in a computational approach.
- Lauber, Birgit S.,Hardegger, Leo A.,Asraful, Alam K.,Lund, Bjarte A.,Dumele, Oliver,Harder, Michael,Kuhn, Bernd,Engh, Richard A.,Diederich, Fran?ois
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supporting information
p. 211 - 221
(2016/01/25)
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- Combretastatin linked 1,3,4-oxadiazole conjugates as a Potent Tubulin Polymerization inhibitors
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A new class of combretastatin linked 1,3,4-oxadiazoles were designed, synthesized and screened for their cytotoxic activity against five human cancer cell lines such as HeLa, DU-145, A549, MDA-MB-231 and B16. These compounds showed significant cytotoxicity with IC50 values in the range 0.118-54.32 μM. Conjugate 5m displayed potent antiproliferative activity against DU-145 cell line. Flow cytometric analysis revealed that these compounds arrested the cell cycle in G2/M phase. Moreover, the tubulin polymerization assay and immunofluorescence analysis indicate that 5m exhibits potent inhibitory effect on the tubulin assembly. Further, DNA fragmentation and Hoecst staining assays confirm that 5m induces apoptosis. Molecular docking studies and competitive binding assay indicated that 5m effectively bind at the colchicine binding site of the tubulin.
- Kamal, Ahmed,Srikanth,Vishnuvardhan,Kumar, G. Bharath,Suresh Babu, Korrapati,Hussaini, S.M. Ali,Kapure, Jeevak Sopanrao,Alarifi, Abdullah
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p. 126 - 136
(2016/03/09)
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- Copper-mediated trifluoromethylation of diaryliodonium salts with difluoromethyltriflate
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The reaction of diaryliodonium salts with difluoromethyltriflate in the presence of TBAT and CuTC gave the corresponding trifluoromethylated arenes in moderate yields. Compared to other difluorocarbene-derived trifluoromethylation reactions, the current one proceeded at mild reaction conditions (room temperature) within short reaction time (5 min).
- Yang, Jing-Yun,Xu, Xiu-Hua,Qing, Feng-Ling
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- Copper-catalysed synthesis of trifluoromethyl(hetero)arenes from di(hetero)aryl-λ3-iodanes
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An efficient synthesis of trifluoromethylated (hetero)arenes has been achieved through the regioselective copper-catalyzed trifluoromethylation of di(hetero)aryl-λ3-iodanes, employing readily available trifluoromethyltrimethylsilane. The reaction works well for both symmetrical and unsymmetrical di(hetero)aryl-λ3-iodanes with good regioselectivity and also tolerates diverse functional groups such as bromo, iodo, cyano, nitro, ester, ketone and enolizable ketone.
- Pandey, Vinay Kumar,Anbarasan, Pazhamalai
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p. 18525 - 18529
(2016/02/27)
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- TCDA: Practical Synthesis and Application in the Trifluoromethylation of Arenes and Heteroarenes
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A practical synthesis of the reagent trimethylsilyl chlorodifluoroacetate (TCDA) is reported on 50 g scale. The trifluoromethylation with TCDA was optimized, and the reaction shows very broad scope with respect to electron-deficient, -neutral, -rich aryl/heteroaryl iodides, as well as excellent functional group tolerability, such as ester, amide, aldehyde, hydroxyl, and carboxylic acid. The reagent was also applied to the late-stage trifluoromethylation of three medicinally relevant compounds. Additionally, the building block trifluoromethylpyridine and one drug related molecule Boc-Fluoxetin were synthesized in 10 g scale by this method, demonstrating its practical applications in process chemistry.
- Wang, Jian,Zhang, Xiaomin,Wan, Zehong,Ren, Feng
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p. 836 - 839
(2016/05/19)
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- Silver-Catalyzed C-H Trifluoromethylation of Arenes Using Trifluoroacetic Acid as the Trifluoromethylating Reagent
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Direct trifluoromethylation of arenes using TFA as the trifluoromethylating reagent was achieved with Ag as the catalyst. This reaction not only provides a new protocol for aryl C-H trifluoromethylation, but the generation of CF3· from TFA may prove useful in other contexts and could potentially be extended to other trifluoromethylation reactions. (Chemical Equation Presented).
- Shi, Guangfa,Shao, Changdong,Pan, Shulei,Yu, Jingxun,Zhang, Yanghui
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supporting information
p. 38 - 41
(2015/07/28)
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- Palladium-Catalyzed Carbonylations of Arylboronic Acids: Synthesis of Arylcarboxylic Acid Ethyl Esters
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An approach for the palladium-catalyzed ethoxycarbonylations of arylboronic acids using diethyl pyrocarbonate as carbon monoxide/carbon dioxide (CO/CO2) surrogate in moderate to good yields has been investigated.
- Liang, Apeng,Han, Shuaijun,Wang, Liang,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
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supporting information
p. 3104 - 3108
(2015/11/03)
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- Copper-mediated trifluoromethylation of diaryliodonium salts with TMSCF3 at room temperature
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A convenient method for the preparation of trifluoromethylated arenes from the reaction of diaryliodonium salts with TMSCF3 in the presence of CuBF4·(MeCN)4 and KF at room temperature within 25 min was developed. This reaction provides a valuable complement to the previously established trifluoromethylation methods.
- Yang, Jing-Yun,Xu, Xiu-Hua,Qing, Feng-Ling
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p. 175 - 180
(2015/10/20)
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- Palladium-catalyzed carbonylations of aryl bromides using paraformaldehyde: Synthesis of aldehydes and esters
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Carbonylation reactions represent useful tools for organic synthesis. However, the necessity to use gaseous carbon monoxide is a disadvantage for most organic chemists. To solve this problem, novel protocols have been developed for conducting palladium-catalyzed reductive carbonylations of aryl bromides and alkoxycarbonylations using paraformaldehyde as an external CO source (CO gas free). Hence, aromatic aldehydes and esters were synthesized in moderate to good yields.
- Natte, Kishore,Dumrath, Andreas,Neumann, Helfried,Beller, Matthias
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supporting information
p. 10090 - 10094
(2015/03/31)
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- New Reagent for Highly Efficient Synthesis of Trifluoromethyl-Substituted Arenes and Heteroarenes
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A new reagent trimethylsilyl chlorodifluoroacetate (TCDA) is reported for the introduction of a -CF3 group to arenes and heteroarenes. Compared with current known reagents, TCDA shows very broad scope with respect to electron-deficient, -neutral, and -rich aryl/heteroaryl iodides as well as excellent functional group tolerance, including ester, amide, aldehyde, hydroxyl, and carboxylic acid. (Chemical Equation Presented).
- Zhang, Xiaomin,Wang, Jian,Wan, Zehong
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supporting information
p. 2086 - 2089
(2015/05/13)
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- Efficient and simple approaches towards direct oxidative esterification of alcohols
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The present article describes novel oxidative protocols for direct esterification of alcohols. The protocols involve successful demonstrations of both "cross" and "self" esterification of a wide variety of alcohols. The cross-esterification proceeds under a simple transition-metal-free condition, containing catalytic amounts of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy)/TBAB (tetra-n-butylammonium bromide) in combination with oxone (potassium peroxo monosulfate) as the oxidant, whereas the self-esterification is achieved through simple induction of Fe(OAc)2/dipic (dipic=2,6-pyridinedicarboxylic acid) as the active catalyst under an identical oxidizing environment. One-pot oxidative esterification: A wide variety of alcohols undergo transition-metal-free (in the presence of oxone/2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)/tetra-n-butylammonium bromide (TBAB)) selective "cross" esterification in moderate to excellent yields (see Figure). The "self" esterification process has however been achieved in the presence of Fe(OAc)2/2,6-pyridinedicarboxylic acid (dipic) as the active catalytic species under a similar oxidizing environment.
- Ray, Ritwika,Jana, Rahul Dev,Bhadra, Mayukh,Maiti, Debabrata,Lahiri, Goutam Kumar
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supporting information
p. 15618 - 15624
(2016/02/18)
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- Polymer supported Pd catalyzed carbonylation of aryl bromides for the synthesis of aryl esters and amides
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A polymer-anchored palladium(ii) catalyst was synthesized and characterized using various spectroscopic techniques. Its catalytic activity was evaluated for the alkoxycarbonylation and aminocarbonylation reactions. These carbonylation reactions were carried out for various substituted aryl bromides using alcohols and amines. Both the reactions were optimized by varying the bases, temperature and solvents. These experiments were carried out under high CO pressure. The catalyst was very stable and can be facilely recovered and reused six times without a significant decrease in its activity and selectivity. the Partner Organisations 2014.
- Islam, Sk Manirul,Ghosh, Kajari,Roy, Anupam Singha,Molla, Rostam Ali
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p. 38986 - 38999
(2014/11/07)
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- Rapid and efficient trifluoromethylation of aromatic and heteroaromatic compounds using potassium trifluoroacetate enabled by a flow system
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Going to the source: The trifluoromethylation of aryl/heteroaryl iodides has been demonstrated using a flow system, thus enabling a rapid rate of reaction. A broad spectrum of trifluoromethylated compounds was prepared in good to excellent yields using CF3CO2K as the trifluoromethyl source. The process has the advantage of short reaction times and uses convenient [CF3] sources. Copyright
- Chen, Mao,Buchwald, Stephen L.
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supporting information
p. 11628 - 11631
(2013/11/06)
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- One-pot tandem Hurtley-retro-Claisen-cyclisation reactions in the synthesis of 3-substituted analogues of 5-aminoisoquinolin-1-one (5-AIQ), a water-soluble inhibitor of PARPs
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Poly(ADP-ribose)polymerase-1 (PARP-1) is an important target for drug design for several therapeutic applications. 5-Aminoisoquinolin-1-one (5-AIQ) is a highly water-soluble lead compound; synthetic routes to 3-substituted analogues were explored. Tandem Hurtley coupling of β-diketones with 2-bromo-3-nitrobenzoic acid, retro-Claisen acyl cleavage and cyclisation gave the corresponding 3-substituted 5-nitroisocoumarins. Treatment with ammonia at high temperature and reduction with tin(II) chloride gave eleven target 3-substituted 5-AIQs, which were all soluble in water (>1% w/v) as their HCl salts. Most were more potent than 5-AIQ as inhibitors of PARP-1 and of PARP-2 in vitro, the most active being 5-amino-3-methylisoquinolin-1-one (PARP-1: IC 50 = 0.23 μM vs IC50 = 1.6 μM for 5-AIQ). Some rationalisation of the SAR was achieved through molecular modelling.
- Woon, Esther C.Y.,Sunderland, Peter T.,Paine, Helen A.,Lloyd, Matthew D.,Thompson, Andrew S.,Threadgill, Michael D.
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p. 5218 - 5227
(2013/09/02)
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- One-pot transformation of carboxylic acids into nitriles
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A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. This method is useful for the conversion of various aromatic and aliphatic carboxylic acids into the corresponding nitriles in a one-pot procedure. A variety of aromatic and aliphatic carboxylic acids were smoothly converted into the corresponding nitriles in good yields in a one-pot procedure by treatment with ethyl iodide/K2CO3/18-crown-6, followed by sodium diisobutyl-tert-butoxyaluminium hydride (SDBBA-H), and finally treatment with molecular iodine or 1,3-diiodo-5,5-dimethylhydantoin (DIH), and aqueous ammonia. Copyright
- Miyagi, Kotaro,Moriyama, Katsuhiko,Togo, Hideo
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p. 5886 - 5892
(2013/09/23)
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- An unusual 1,2-aryl shift in palladium-catalyzed cross-coupling ethoxycarbonylation of arylboronic acids with α-iminoesters
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The Pd-catalyzed cross-coupling ethoxycarbonylation of aryl boronic acids with N-aryl-α-iminoesters affords aryl carboxylic esters via carbonyl-imino σ bond cleavage. This unprecedented mode of reaction allows regioselective installation of the ethoxycarbonyl group into target molecules. Mechanism studies have revealed that an unusual 1,2-aryl shift process is involved in the transformation. The Royal Society of Chemistry.
- Qian, Cheng,Chen, Jiayan,Fu, Meiqin,Zhu, Shiya,Chen, Wen-Hua,Jiang, Huanfeng,Zeng, Wei
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p. 6013 - 6022
(2013/09/12)
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- Silver-mediated trifluoromethylation of aryldiazonium salts: Conversion of amino group into trifluoromethyl group
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A novel strategy for aromatic trifluoromethylation by converting aromatic amino group into CF3 group is reported herein. This method, which can be considered as trifluoromethylation variation of the classic Sandmeyer reaction, uses readily available aromatic amines as starting materials and is performed under mild conditions.
- Wang, Xi,Xu, Yan,Mo, Fanyang,Ji, Guojing,Qiu, Di,Feng, Jiajie,Ye, Yuxuan,Zhang, Songnan,Zhang, Yan,Wang, Jianbo
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supporting information
p. 10330 - 10333
(2013/08/23)
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- Trifluoromethylation of 1-aryl-3,3-diisopropyltriazenes
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A new method for the trifluoromethylation of functionalized aromatic diisopropyltriazenes is described. In a facile two-step, one-pot synthesis, various functionalized trifluoromethyl-substituted arenes are accessible in mostly good yields by using methyl iodide as iodination agent and the trifluoromethylation system (trifluoromethyl)trimethylsilane/potassium fluoride/copper iodide. This concept could be expanded to perfluoroethylation as well as ethoxycarbonyldifluoromethylation reactions. Copyright
- Hafner, Andreas,Braese, Stefan
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supporting information
p. 996 - 1000
(2013/05/08)
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- Pd-catalyzed aldehyde to ester conversion: A hydrogen transfer approach
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Aliphatic and aromatic aldehydes are successfully converted into their corresponding esters using Pd(OAc)2 and XPhos. This approach utilizes a hydrogen transfer protocol: concomitant reduction of acetone to isopropanol provides an inexpensive and sustainable approach that mitigates the need for other oxidants.
- Tschaen, Brittany A.,Schmink, Jason R.,Molander, Gary A.
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supporting information
p. 500 - 503
(2013/04/11)
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- Fluoroform-derived CuCF3 for low-cost, simple, efficient, and safe trifluoromethylation of aryl boronic acids in air
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Easy does it: Aryl boronic acids undergo smooth and selective trifluoromethylation with low-cost fluoroform-derived CuCF3 in DMF in non-dried air. The reaction occurs under mild conditions (1 atm, room temperature), exhibits unprecedented funct
- Novak, Petr,Lishchynskyi, Anton,Grushin, Vladimir V.
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supporting information; experimental part
p. 7767 - 7770
(2012/08/29)
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- Facile preparation of aromatic esters from aromatic bromides with ethyl formate or DMF and molecular iodine via aryllithium
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Various aromatic bromides were treated with n-BuLi and subsequently with ethyl formate, followed by the reaction with ethanol and molecular iodine in the presence of K2CO3 to provide the corresponding aromatic ethyl esters in good yields. Moreover, aromatic bromides could be transformed into the corresponding aromatic methyl esters in good yields by the treatment with n-BuLi and subsequently with DMF, followed by the reaction with methanol, molecular iodine, and K2CO3. Some aromatics could be also converted into the corresponding aromatic esters in good yields by the treatment with n-BuLi, and subsequently with ethyl formate or DMF, followed by the reaction with molecular iodine and K2CO3. The present reactions offer a novel route for the transition-metal-free, carbon-monoxide-free, and therefore environmentally benign one-pot conversion of aromatic bromides and aromatics into aromatic esters.
- Ushijima, Sousuke,Moriyama, Katsuhiko,Togo, Hideo
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experimental part
p. 4701 - 4709
(2012/07/28)
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- FLUOROALKYLATION METHODS AND REAGENTS
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A method of forming a fluorinated molecular entity includes reacting in a reaction mixture an aromatic halide, copper, a fluoroalkyl group, and a ligand. The aromatic halide includes an aromatic group and a halogen substituent bonded to the aromatic group. The ligand includes at least one group-V donor selected from phosphorus and an amine. The overall molar ratio of copper to aromatic halide in the reaction mixture is from 0.2 to 3. The method further includes forming a fluoroalkylarene including the aromatic group and the fluoroalkyl group bonded to the aromatic group. A composition, which may be used in the method, consists essentially of copper, the fluoroalkyl group, and the ligand, where the molar ratio of copper to the fluoroalkyl group is approximately 1.
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Page/Page column 7; 31
(2012/03/11)
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- A continuous-flow approach to palladium-catalyzed alkoxycarbonylation reactions
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Using a continuous-flow approach, it is possible to perform alkoxycarbonylation reactions of aryl iodides. Optimized reactor design allows for adequate mixing of gaseous and liquid reagents. Reactions are performed at rates of around 3 mL/min and at concentrations of 1 M, allowing for significant volumes to be processed per unit time. Palladium acetate (0.5 mol %) is used as the catalyst without the need for an additional ligand.
- Kelly, Christopher B.,Lee, Christopher,Mercadante, Michael A.,Leadbeater, Nicholas E.
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experimental part
p. 717 - 720
(2011/12/01)
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- A clean, palladium-catalyzed oxidative esterification of aldehydes using benzyl chloride
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A highly efficient, mild, simple and clean procedure is presented for the one-pot oxidation of aromatic and aliphatic aldehydes to their corresponding ethyl esters using benzyl chloride as the oxidant under palladium-catalyzed conditions. The reaction is complete in just 30 min under microwave irradiation and inert conditions are not required to obtain good to excellent yields (65-93%) of isolated products.
- Heropoulos, Georgios A.,Villalonga-Barber, Carolina
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experimental part
p. 5319 - 5322
(2011/10/31)
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- A ligand-free copper-catalyzed decarboxylative trifluoromethylation of aryliodides with sodium trifluoroacetate using Ag2O as a promoter
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A practical and ligand-free Cu-catalyzed decarboxylative trifluoromethylation of aryl iodides with sodium trifluoroacetate using Ag 2O as a promoter was reported. A variety of trifluoromethyl- substituted aromatics are synthesized in moderate to excellent yields and with wide functional-group tolerance under relatively mild reaction conditions. Georg Thieme Verlag Stuttgart · New York.
- Li, Yaming,Chen, Tao,Wang, Huifeng,Zhang, Rong,Jin, Kun,Wang, Xiuna,Duan, Chunying
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supporting information; experimental part
p. 1713 - 1716
(2011/09/12)
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- Copper-catalyzed trifluoromethylation of aryl boronic acids using a CF 3+ reagent
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A copper-catalyzed process for trifluoromethylation of aryl, heteroaryl, and vinyl boronic acids has been developed. The reaction is conducted under mild conditions and shows tolerance to moisture and a variety of functional groups.
- Xu, Jun,Luo, Dong-Fen,Xiao, Bin,Liu, Zhao-Jing,Gong, Tian-Jun,Fu, Yao,Liu, Lei
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supporting information; experimental part
p. 4300 - 4302
(2011/06/21)
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- A broadly applicable copper reagent for trifluoromethylations and perfluoroalkylations of aryl iodides and bromides
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(Chemical Presented) Well compatible: The trifluoromethylations and perfluoroalkylations of aryl iodides and some aryl bromides with trifluoromethyl and perfluoroalkylcopper(I) phenanthroline complexes occur with broad scope at 25-50 8C (see scheme). The trifluoromethyl complex is prepared from inexpensive reagents and can be used in situ or isolated. The reactions tolerate a range of substituents and also occur with heteroaromatic systems.
- Morimoto, Hiroyuki,Tsubogo, Tetsu,Litvinas, Nichole D.,Hartwig, John F.
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supporting information; experimental part
p. 3793 - 3798
(2011/05/15)
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- Aromatic trifluoromethylation catalytic in copper
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Cu(i)-diamine complexes were found to catalyse the trifluoromethylation of aryl iodides. In the presence of a small amount of CuX (X = Cl, Br, I) and 1,10-phenanthroline (phen), the cross-coupling reactions of iodoarenes with trifluoromethylsilanes proceeded smoothly to afford trifluoromethylated aromatics in good yields.
- Oishi, Masahiro,Kondo, Hideaki,Amii, Hideki
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supporting information; experimental part
p. 1909 - 1911
(2009/10/17)
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- Alkoxycarbonylation of aryl iodides using gaseous carbon monoxide and pre-pressurized reaction vessels in conjunction with microwave heating
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The microwave-promoted alkoxycarbonylation of aryl iodides using reaction vessels pre-pressurized with carbon monoxide is reported. Reactions are performed using 0.1 mol% palladium acetate as catalyst, DBU as base and are complete within 20-30 min. A range of aryl iodide substrates can be converted to the corresponding esters using this methodology. Primary and secondary alcohols work well whereas a tertiary alcohol substrate proves less reactive. The potential for scale-up of the reaction has also been explored. The Royal Society of Chemistry.
- Kormos, Chad M.,Leadbeater, Nicholas E.
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- Use of polyfuntionalized ethylene synthons: Convenient synthesis of biologically active trifluoromethyl containing N-substituted-benzoylpyrazoles and triazole
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Ten biologically active trifluoromethy1 containing N-substituted- benzoylpyrazoles (3a-d, 4a-d, and 6a, b) and one triazole analogue 5 have been conveniently synthesized from four versatile polyfunctionalized ethylene synthons and one novel synthon N-cyan
- Li, Ming,Wen, Lirong,Wang, Xiao,Yao, Changsheng,Fu, Weijun,Zhao, Guilong,Hu, Fangzhong,Yang, Huazheng
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p. 483 - 488
(2007/10/03)
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- Metal cation-exchanged montmorillonite(Mn+-mont)-catalysed carbonyl-ene reactions
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Metal cation-exchanged montmorillonite (Mn+-mont) works in acetonitrile at 80°C as a Lewis acid catalyst for the intermolecular carbonyl-ene reaction of α-methylstyrenes with paraformaldehyde to give the corresponding homoallylic alcohols, Zr4+-mont being the most effective of the many Mn+-mont catalysts examined. Similarly, the catalyst is also useful for the highly stereoselective intramolecular cyclization of citronellals to afford isopulegols, the reaction being much faster. Regeneration of the catalyst is confirmed for Zr4+-mont, which can be effectively recycled at least five times.
- Tateiwa, Jun-Ichi,Kimura, Akihiro,Takasuka, Masaaki,Uemura, Sakae
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p. 2169 - 2174
(2007/10/03)
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- The Diels-Alder Route to Trifluoromethyl-Substituted Carbo- and Heterocycles
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Starting with 1,1,1-trifluoroacetone, 3-(trifluoromethyl)-1-(trimethylsilyloxy)-1,3-butadiene (2) has been prepared as a mixture of (Z) and (E) isomers.The diene undergoes cycloaddition reactions with a variety of dienophiles affording trifluoromethyl-substituted carbocyclic and heterocyclic compounds 7-11 in yields ranging from moderate to good. - Keywords: Trifluoromethyl substituents / Carbocycles / Heterocycles / Diels-Alder reactions / Electron-rich/electron-poor diene
- Schlosser, Manfred,Keller, Holger
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p. 1587 - 1590
(2007/10/02)
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- Methyl 3-Oxa-ω-fluorosulfonylperfluoropentanoate: a Versatile Trifluoromethylating Agent for Organic Halides
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Methyl 3-oxa-ω-fluorosulfonylperfluoropentanoate FSO2CF2CF2OCF2CO2Me 1, prepared through the reaction of readily available ICF2CF2OCF2CF2SO2F and SO3 followed by MeOH, is a very convenient trifluoromethylating agent; in the presence of copper(I) iodide, 1 not only reacts with vinyl, benzyl allyl, phenyl iodides and bromides, but also with aryl chlorides to give the corresponding trifluoromethyl compounds in moderate to high yield; a probable reaction mechanism is proposed.
- Chen, Qing-Yun,Duan, Jian-Xing
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p. 1389 - 1391
(2007/10/02)
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- An Efficient Electrochemical Trifluoromethylation of Aromatic Halides with Bromotrifluoromethane and a Sacrificial Copper Anode
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The electrochemical cross-coupling of bromotrifluoromethane with aromatic or heteroaromatic iodides and bromides is successfully achieved in a one-compartment electrolysis cell fitted with a sacrificial copper anode.
- Paratian, J. M.,Sibille, S.,Perichon, J.
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- A NOVEL AND CONVENIENT METHOD FOR TRIFLUOROMETHYLATION OF ORGANIC HALIDES USING CF3SiR'3/KF/Cu(I) SYSTEM
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Fluoride ion induced cross-coupling reaction of organic halides with trifluoromethyltrialkylsilanes takes place in the presence of Cu(I) salts under mild reaction conditions to give the corresponding trifluoromethylated products in high yields.
- Urata, Hisao,Fuchikami, Takamasa
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- Substituent Effects on Benzyl Radical ESR Hyperfine Coupling Constants. The ?α*Scale Based upon Spin Delocalization
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The electron spin resonance spectra of 21 para- and meta-substituted benzyl radicals have been analyzed.A substituent constant, ?α*, has been defined from the benzylic α-hydrogen hyperfine coupling constant.The ?α* constant reflects the component of energy that may be attributed to spin delocalization in a substituted benzyl radical in comparison to the unsubstituted radical.For the derivatives studied, para substitution is stabilizing, except when fluorine is the substituent; meta substitution destabilizes the benzyl radical.A series of radical reactions is reexamined with an extended Hammett relation.The relative importance of spin delocalization vs. polar effects is assessed by the ratio of ρ* to ρ.The importance of choosing substituents for which ?a* and ? differ widely for such an assessment is emphasized.
- Dust, Julian M.,Arnold, Donald R.
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p. 1221 - 1227
(2007/10/02)
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