- Acyl fluorides from carboxylic acids, aldehydes, or alcohols under oxidative fluorination
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We describe a novel reagent system to obtain acyl fluorides directly from three different functional group precursors: carboxylic acids, aldehydes, or alcohols. The transformation is achieved via a combination of trichloroisocyanuric acid and cesium fluoride, which facilitates the synthesis of various acyl fluorides in high yield (up to 99%). It can be applied to the late-stage functionalization of natural products and drug molecules that contain a carboxylic acid, an aldehyde, or an alcohol group.
- Liang, Yumeng,Zhao, Zhengyu,Taya, Akihito,Shibata, Norio
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supporting information
p. 847 - 852
(2021/02/06)
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- Homoleptic Bis(trimethylsilyl)amides of Yttrium Complexes Catalyzed Hydroboration Reduction of Amides to Amines
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Homoleptic lanthanide complex Y[N(TMS)2]3 is an efficient homogeneous catalyst for the hydroboration reduction of secondary amides and tertiary amides to corresponding amines. A series of amides containing different functional groups such as cyano, nitro, and vinyl groups were found to be well-tolerated. This transformation has also been nicely applied to the synthesis of indoles and piribedil. Detailed isotopic labeling experiments, control experiments, and kinetic studies provided cumulative evidence to elucidate the reaction mechanism.
- Ye, Pengqing,Shao, Yinlin,Ye, Xuanzeng,Zhang, Fangjun,Li, Renhao,Sun, Jiani,Xu, Beihang,Chen, Jiuxi
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supporting information
p. 1306 - 1310
(2020/02/22)
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- Carbonylative C?C Bond Activation of Electron-Poor Cyclopropanes: Rhodium-Catalyzed (3+1+2) Cycloadditions of Cyclopropylamides
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Rh-catalyzed carbonylative C?C bond activation of cyclopropylamides generates configurationally stable rhodacyclopentanones that engage tethered alkenes in (3+1+2) cycloadditions. These studies provide the first examples of multicomponent cycloadditions t
- Dalling, Andrew G.,Yamauchi, Takayuki,McCreanor, Niall G.,Cox, Lydia,Bower, John F.
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supporting information
p. 221 - 225
(2018/12/11)
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- Synthesis of amides from acid chlorides and amines in the bio-based solvent Cyrene
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Cyrene as a bio-alternative dipolar aprotic solvent: a waste minimizing and molar efficient protocol for the synthesis of amides from acid chlorides and primary amines in the bio-available solvent Cyrene is disclosed. This protocol removed the use of toxic solvents, such as dimethylformamide and dichloromethane. A simple aqueous work-up procedure for the removal of the high boiling solvent Cyrene resulted in up to a 55-fold increase in molar efficiency (Mol E.%) versus standard operating procedures. In order to rapidly compare the molar efficiency of this process against other methodologies an Excel based Mol. E% calculator was developed that automates many of the calculations. An investigation into the hydration of Cyrene found that it readily hydrates to form a geminal diol in the presence of water and that this process is exothermic.
- Bousfield, Thomas W.,Pearce, Katharine P. R.,Nyamini, Simbarashe B.,Angelis-Dimakis, Athanasios,Camp, Jason E.
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supporting information
p. 3675 - 3681
(2019/07/09)
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- Fe(ClO 4) 3 ·h 2 O-Catalyzed Ritter Reaction: A Convenient Synthesis of Amides from Esters and Nitriles
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An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with esters catalyzed by Fe(ClO 4) 3 ·H 2 O is described. Fe(ClO 4) 3 ·H 2 O is an economically efficient catalyst for the Ritter reaction under solvent-free conditions. Reactions of a range of esters (benzyl, sec-alkyl, and tert-butyl esters) with nitriles (primary, secondary, tertiary, and aryl nitriles) were performed to provide the corresponding amides in high to excellent yields.
- Feng, Chengliang,Yan, Bin,Yin, Guibo,Chen, Junqing,Ji, Min
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p. 2257 - 2264
(2018/10/20)
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- Synthesis of acyl fluorides via photocatalytic fluorination of aldehydic C-H bonds
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Acyl fluorides are versatile acylating agents owing to their unique stability. Their synthesis, however, can present challenges and is typically accomplished through deoxyfluorination of carboxylic acids. Here, we demonstrate that acyl fluorides can be prepared directly from aldehydes via a C(sp2)-H fluorination reaction involving the inexpensive photocatalyst sodium decatungstate and electrophilic fluorinating agent N-fluorobenzenesulfonimide. This convenient fluorination strategy enables direct conversion of aliphatic and aromatic aldehydes into acylating agents.
- Meanwell, Michael,Lehmann, Johannes,Eichenberger, Marc,Martin, Rainer E.,Britton, Robert
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supporting information
p. 9985 - 9988
(2018/09/11)
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- High-load, oligomeric dichlorotriazine: A versatile ROMP-derived reagent and scavenger
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(Chemical Equation Presented) A new high-load, soluble oligomeric dichlorotriazine (ODCT) reagent derived from ring-opening metathesis polymerization (ROMP) is reported as an effective coupling reagent, scavenger of nucleophilic species, and activator of DMSO for the classic Swern oxidations. Two variants of this reagent 2GODCT 4 and 1GODCT 16, possessing theoretical loads of 5.3 and 7.3 mmol/g, respectively, have been synthesized. Preparation was accomplished via simple synthetic protocols affording free flowing powders, amenable for large-scale production. Removal of the spent oligomeric reagent was achieved via either precipitation of the spent reagent or simple filtration utilizing a silica SPE, followed by solvent removal, to deliver products in excellent yield and purity. In addition, the corresponding norbornenyl monomer 3 was successfully demonstrated in a couple-ROMP-filter protocol utilizing in situ polymerization, achieving comparable results versus the corresponding oligomeric variant.
- Rolfe, Alan,Probst, Donald A.,Volp, Kelly A.,Omar, Iman,Flynn, Daniel L.,Hanson, Paul R.
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supporting information; experimental part
p. 8785 - 8790
(2009/04/11)
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- Antikinetoplastid antimitotic activity and metabolic stability of dinitroaniline sulfonamides and benzamides
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N1-Phenyl-3,5-dinitro-N4,N4-di-n-propylsulfanilamide (1) and N1-phenyl-3,5-dinitro-N4,N4-di-n-butylsulfanilamide (2) show potent in vitro antimitotic activity against kinetoplastid parasites but display poor in vivo activity. Seventeen new dinitroaniline sulfonamide and eleven new benzamide analogs of these leads are reported here. Nine of the sulfonamides display in vitro IC50 values under 500 nM against African trypanosomes, and the most active antikinetoplastid compounds also inhibit the in vitro assembly of purified leishmanial tubulin with potencies similar to that of 2. While several of the potent compounds are rapidly degraded by rat liver S9 fractions in vitro, N1-(3-hydroxy)phenyl-3,5-dinitro-N4,N4-di-n-butylsulfanilamide (21) displays an IC50 value of 260 nM against African trypanosomes in vitro and is more stable than 2 in the in vitro metabolism assay.
- George, Tesmol G.,Johnsamuel, Jayaseharan,Delfin, Dawn A.,Yakovich, Adam,Mukherjee, Mitali,Phelps, Mitch A.,Dalton, James T.,Sackett, Dan L.,Kaiser, Marcel,Brun, Reto,Werbovetz, Karl A.
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p. 5699 - 5710
(2007/10/03)
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- Ring-expanding reaction of cyclopropyl amides with triphenylphosphine and carbon tetrahalide
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We succeeded in activating cyclopropyl amides (monoactivated cyclopropane) through the corresponding imidoyl halides prepared in situ in the presence of 2 equiv of PPh3 and 1 equiv of CX4, and the ring-expanding products (N-substituted pyrrolidin-2-ones) were obtained in good yields. The reaction mechanism was investigated on the basis of oxygen-18 tracer experiment.
- Yang, Yong-Hua,Shi, Min
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p. 8645 - 8648
(2007/10/03)
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- Kinetics and mechanism of the aminolysis of S-phenyl cyclopropanecarboxylates in acetonitrile
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The kinetics and mechanism of the aminolysis of S-phenyl cyclopropanecarboxylates [cyclo-C3H5C(=O)- SC6H4Z] with benzylamines (XC6H4CH2NH2) were investigated in aceton
- Oh, Hyuck Keun,Yun Lee, Jae,Lee, Hai Whang,Lee, Ikchoon
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p. 473 - 476
(2007/10/03)
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- Kinetics and mechanism of the aminolysis of phenyl cyclopropanecarboxylates in acetonitrile
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Kinetic studies of the reaction of Z-phenyl cyclopropanecarboxylates with X-benzylamines in acetonitrile at 55.0 °C have been carried out. The reaction proceeds by a stepwise mechanism in which the rate-determining step is the breakdown of the zwitterionic tetrahedral intermediate, T±, with a hydrogen-bonded four-center type transition state (TS). These mechanistic conclusions are drawn based on (i) the large magnitude of ρX and ρZ, (ii) the normal kinetic isotope effects (KH/kD > 1.0) involving deuterated benzylamine nucleophiles, (iii) the positive sign of ρXZ and the larger magnitude of ρXZ than that for normal SN2 processes, and lastly (iv) adherence to the reactivity-selectivity principle (RSP) in all cases.
- Koh, Han Joong,Shin, Chul Ho,Lee, Hai Whang,Lee, Ikchoon
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p. 1329 - 1332
(2007/10/03)
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