- Electrophile-induced nucleophilic substitution of the nido- dicarbaundecaborate anion nido-7,8-c2b9h12 by conjugated heterodienes
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Substitution of the dicarbaundecaborate anion nido-7,8-C2B9H12 (1) by precise hydride abstraction followed by nucleophilic attack usually leads to symmetric products 10-R-nido-7,8-C2B9H11. However, thioacetamide (MeC(S)NH2) as nucleophile and acetone/AlCl3 as hydride abstractor gave asymmetric 9-[MeC(NHiPr)S]-nido-7,8-C2B9H11 (2), whereas N,N-dimethylthioacetamide (MeC(S)NMe2) gave the expected symmetric 10-[MeC(NMe2)S]-nido-7,8-C2B9H11 (4). For the formation of 2, acetone and thioacetamide are assumed to give the intermediate MeC(S)N(CMe2) (3), which then attacks 1 with formation of 2. Similarly, reaction of acetyliminium chloride [MeC(O)NH(CPh2)]Cl (5) with 1 in THF gave a mixture of 9-and 10-substituted [MeC(NHCHPh2)O]-nido-7,8-C2B9H11 (6 and 7, respectively). These reactions are the first examples in which compounds (here heterodienes) that unite the functionalities of both hydride acceptor and nucleophilic site react with 1 in a bimolecular fashion. Furthermore, the analogous reaction of 1 and 5 (in an equilibrium mixture with acetyl chloride and benzophenone imine) in MeCN afforded 10-[MeC(NCPh2)NH]-nido-7,8-C2B9H11 (8) and MeC(O)NHCHPh2 (9).
- Frank, Rene,Adhikari, Anup Kumar,Auer, Henry,Hey-Hawkins, Evamarie
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Read Online
- Decarboxylative Ritter-Type Amination by Cooperative Iodine (I/III)─Boron Lewis Acid Catalysis
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Recent years have witnessed important progress in synthetic strategies exploiting the reactivity of carbocations via photochemical or electrochemical methods. Yet, most of the developed methods are limited in their scope to certain stabilized positions in molecules. Herein, we report a metal-free system based on the iodine (I/III) catalytic manifold, which gives access to carbenium ion intermediates also on electronically disfavored benzylic positions. The unusually high reactivity of the system stems from a complexation of iodine (III) intermediates with BF3. The synthetic utility of our decarboxylative Ritter-type amination protocol has been demonstrated by the functionalization of benzylic as well as aliphatic carboxylic acids, including late-stage modification of different pharmaceutical molecules. Notably, the amination of ketoprofen was performed on a gram scale. Detailed mechanistic investigations by kinetic analysis and control experiments suggest two mechanistic pathways.
- Narobe, Rok,Murugesan, Kathiravan,Schmid, Simon,K?nig, Burkhard
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p. 809 - 817
(2022/01/15)
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- Tropylium-promoted Ritter reactions
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The Ritter reaction used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuableN-alkyl amide products. However, this reaction has not been frequently used in modern organic synthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the tropylium ion to promote the Ritter reaction. This method works well on a range of alcohol and nitrile substrates, giving the corresponding products in good to excellent yields. This reaction protocol is amenable to microwave and continuous flow reactors, offering an attractive opportunity for further applications in organic synthesis.
- Doan, Son H.,Hussein, Mohanad A.,Nguyen, Thanh Vinh
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supporting information
p. 8901 - 8904
(2021/09/10)
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- C-H Amination via Electrophotocatalytic Ritter-Type Reaction
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A method for C-H bond amination via an electrophotocatalytic Ritter-Type reaction is described. The reaction is catalyzed by a trisaminocyclopropenium (TAC) ion in an electrochemical cell under irradiation. These conditions convert benzylic C-H bonds to acetamides without the use of a stoichiometric chemical oxidant. A range of functionality is shown to be compatible with this transformation, and several complex substrates are demonstrated.
- Lambert, Tristan H.,Shen, Tao
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supporting information
p. 8597 - 8602
(2021/06/28)
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- Iodolopyrazolium Salts: Synthesis, Derivatizations, and Applications
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The synthesis of iodolopyrazolium triflates via an oxidative cyclization of 3-(2-iodophenyl)-1H-pyrazoles is described. The reaction is characterized by a broad substrate scope, and various applications of these novel cyclic iodolium salts acting as useful synthetic intermediates are demonstrated, in particular in site-selective ring openings. This was finally applied to generate derivatives of the anti-inflammatory drug celecoxib. Their application as highly active halogen-bond donors is shown as well.
- Boelke, Andreas,Caspers, Lucien D.,Kuczmera, Thomas J.,Lork, Enno,Nachtsheim, Boris J.
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supporting information
p. 7261 - 7266
(2020/10/05)
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- New approach for induction of alkyl moiety to aliphatic amines by NaBH(OAc)3 with carboxylic acid
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We had found the novel N-alkylation method, which utilizes carboxylic acids as alkyl sources with sodium triacetoxyborohydride [NaBH(OAc)3]. Our methodology had been revealed to have some advantages over the reported similar procedures. Through
- Tamura, Satoru,Sugawara, Aoi,Sato, Erika,Sato, Fuka,Sato, Keigo,Kawano, Tomikazu
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supporting information
(2020/04/15)
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- Chemoselective formation of C–N bond in wet acetonitrile using amberlyst-15(H) as a recyclable catalyst
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An economically efficient and environmentally benign protocol for the chemoselective one-pot synthesis of diversely N-substituted amides has been developed in good yield through the reaction of benzylic secondary alcohols as well as aliphatic tertiary alcohols and alkyl/aryl nitriles. Commercially available Amberlyst-15(H) has been utilized at 80 °C as an air-stable and reusable heterogeneous inexpensive solid acid catalyst without any anhydrous and inert environment. The attractive features of the present synthetic protocol are mild reaction conditions, short reaction time, excellent chemoselectivity, high atom economy and tolerance of various sensitive moieties.
- Nandy, Sneha,Das, Asit Kumar,Bhar, Sanjay
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supporting information
p. 3326 - 3336
(2020/08/13)
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- Environmentally benign decarboxylative: N-, O-, and S-Acetylations and acylations
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An operationally simple and general method for acetylation and acylation of a wide variety of substrates (amines, alcohols, phenols, thiols, and hydrazones) has been reported. Meldrum's acid and its derivatives have been used as an air-stable, non-volatile, cost-effective, and easy to handle acetylating/acylating agent. Easily separable byproducts (CO2 and acetone) allowed the isolation of analytically pure acetylated products without the requirement of work-up and any chromatography. This journal is
- Ghosh, Santanu,Purkait, Anisha,Jana, Chandan K.
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supporting information
p. 8721 - 8727
(2020/12/30)
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- Dual Nickel- And Photoredox-Catalyzed Reductive Cross-Coupling of Aryl Halides with Dichloromethane via a Radical Process
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The first catalytic strategy to harness a new chloromethane radical from dichloromethane under dual Ni/photoredox catalytic conditions has been developed. Compared with traditional two-electron reductive process associated with metallic reductants, this method via a single-electron approach can proceed under exceptionally mild conditions (visible light, ambient temperature, no strong base) and exhibits complementary reactivity patterns. It affords a broad scope of many functional groups, including alkenyl, which suffers cyclopropanation in previous routes. The diarylmethane-d2 compounds can be readily available with this transformation.
- Xu, Tao,Xu, Wenhao,Zheng, Purui
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supporting information
(2020/11/13)
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- Environmentally Benign Ritter Reaction Using Bismuth Salts as a Catalyst
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We developed an environmentally benign Ritter reaction of alcohols with nitriles using a commercially available bismuth salt as a less harmful catalyst. The detailed reaction profiles revealed that consumption of the ether by-product as the reaction proceeded was the key for optimizing this reaction, and the yield of the target amide was improved by adding a small amount of water. This finding clearly reveals the significance of using a bismuth salt as the catalyst, as it is not deactivated in the presence of water. This catalyst system has a broad substrate scope, and even with 1 mol-% of the catalyst, the reaction progresses smoothly. It is also possible to react stoichiometric amounts of nitriles and alcohols, thus reducing the amount of organic solvent required for the reaction. Furthermore, as the inexpensive bismuth catalyst can be easily removed using aqueous hydrochloric acid, a purification process that only required washing and drying without any organic solvents was successfully established.
- Ueno, Masaharu,Kusaka, Ryo,Ohmura, Satoshi D.,Miyoshi, Norikazu
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supporting information
p. 1796 - 1800
(2019/02/07)
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- Convergent Ditopic Receptors Enhance Anion Binding upon Alkali Metal Complexation for Catalyzing the Ritter Reaction
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A supramolecular approach to catalyzing the Ritter reaction by utilizing enhanced anion-binding affinity in the presence of alkali metal cations was developed with ditopic hydrogen-bonded amide macrocycles. With prebound cations in the macrocycle, particu
- Kang, Kang,Nagarajan, Sangaraiah,Chen, Lixi,Deng, Pengchi,Shen, Xin,Fu, Kuirong,Feng, Wen,Yuan, Lihua,Lohrman, Jessica A.,Johnson, Darren W.
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supporting information
p. 652 - 655
(2019/04/10)
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- Iodine(III) Derivatives as Halogen Bonding Organocatalysts
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Hypervalent iodine(III) derivatives are known as versatile reagents in organic synthesis, but there is only one previous report on their use as Lewis acidic organocatalysts. Herein, we present first strong indications for the crucial role of halogen bonding in this kind of catalyses. To this end, the solvolysis of benzhydryl chloride and the Diels–Alder reaction of cyclopentadiene with methyl vinyl ketone served as benchmark reactions for halide abstraction and the activation of neutral compounds. Iodolium compounds (cyclic diaryl iodonium species) were used as activators or catalysts, and we were able to markedly reduce or completely switch off their activity by sterically blocking one or two of their electrophilic axes. Compared with previously established bidentate cationic halogen bond donors, the monodentate organoiodine derivatives used herein are at least similarly active (in the Diels–Alder reaction) or even decidedly more active (in benzhydryl chloride solvolysis).
- Heinen, Flemming,Engelage, Elric,Dreger, Alexander,Weiss, Robert,Huber, Stefan M.
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supporting information
p. 3830 - 3833
(2018/03/09)
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- Air-stable Bis(pentamethylcyclopentadienyl) Zirconium Perfluorooctanesulfonate as an Efficient and Recyclable Catalyst for the Synthesis of N-substituted Amides
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Bis(pentamethylcyclopentadienyl) zirconium perfluorooctanesulfonate is an air-stable and water-tolerant Lewis acid. This complex exhibited good thermal stability and high solubility in polar organic solvents. The compound showed relatively strong acidity, with an acid strength of 0.8Ho≤3.3, and high catalytic efficiency for the synthesis of N-substituted amides via the reaction of carboxylic acids with amines, the Ritter reaction of nitriles with alcohols, and the amination of alcohols with amides. Moreover, the complex had good reusability. This catalytic system affords a simple and efficient way to synthesize N-substituted amides.
- Li, Ningbo,Wang, Lingxiao,Zhang, Liting,Zhao, Wenjie,Qiao, Jie,Xu, Xinhua,Liang, Zhiwu
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p. 3532 - 3538
(2018/08/01)
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- 1,1-Diacyloxy-1-phenylmethanes as versatile N-acylating agents for amines
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1,1-Diacyloxy-1-phenylmethanes and 1-pivaloxy-1-acyloxy-1-phenylmethanes have been used as bench stable N-acylating reagents for primary and secondary amines and anilines under solvent-free conditions to afford their corresponding amides in good yield.
- Chapman, Robert. S.L.,Tibbetts, Joshua. D.,Bull, Steven. D.
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p. 5330 - 5339
(2018/06/15)
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- An Atom-Economical Route to Substituted β-Arylethyl Ketones: Phosphomolybdic Acid-Catalyzed Carbohydroxylation of Terminal Alkynes in Organic Carbonate
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A highly efficient and atom-economical route for the synthesis of substituted β-arylethyl ketones was developed by using cheap phosphomolybdic acid (H3PMo12O40) as catalyst and non-volatile propylene carbonate (PC) as green solvent via the carbohydroxylation of terminal alkynes with benzylic alcohols under mild conditions. Various functional groups on the benzylic alcohols and terminal alkynes were tolerated, giving the corresponding substituted β-arylethyl ketones as products in good to excellent yields (up to 95%). It is worth noting that a turnover number (TON) of up to 520 was achieved in the protocol. The mechanism investigation showed that PC might stabilize the heteropoly anion and the carbocation intermediate thus facilitating the carbohydroxylation reaction. (Figure presented.).
- Yang, Guo-Ping,Zhang, Nan,Ma, Nuan-Nuan,Yu, Bing,Hu, Chang-Wen
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p. 926 - 932
(2017/03/27)
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- Manganese(III) acetate catalyzed oxidative amination of benzylic C(sp3)-H bonds with nitriles
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Mn-Catalyzed oxidative amination of benzylic C(sp3)-H bonds with nitriles is disclosed, which enables the synthesis of a broad range of secondary amides in moderate to excellent yields under mild conditions. The interaction between Mn(iii) and DDQ facilitates the oxidation and makes it highly efficient and selective.
- Zhang, Yaxing,Dong, Jianyu,Liu, Lixin,Liu, Long,Zhou, Yongbo,Yin, Shuang-Feng
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supporting information
p. 2897 - 2901
(2017/04/11)
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- Method for preparing amide from aryl methane derivative and nitrile
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The invention provides a simple and efficient method for directly preparing an amide compound from an aryl methane derivative and nitrile. In the method, manganese triacetate dihydrate is used as a catalyst, and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone(DDQ) is used as an oxidizing agent. The method has the characteristics that raw materials are cheap and easy to obtain, the source of the nitrile is wide, reaction conditions are mild, the applicability is wide and the like. The method solves the problems that ceric ammonium nitrate (CAN) and a fluorine agent which are used by a method for directly synthesizing amide by using aryl methane and nitrile compounds are hard to treat, atomic economy is poor, the source of the nitrile is narrow and the like.
- -
-
Paragraph 0023-0025
(2017/05/10)
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- Indium-Triflate-Catalyzed Ritter Reaction in Liquid Sulfur Dioxide
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The use of liquid sulfur dioxide as a reaction solvent facilitates the Ritter reaction between alcohols and nitriles. In(OTf)3 was found to be a viable catalyst for this transformation. The newly developed catalytic conditions for the Ritter reaction were successfully applied to the synthesis of various amides, which were formed in good to excellent yields. The catalytic activation of secondary alcohols for Ritter reactions in liquid sulfur dioxide was also found to be effective.
- Posevins, Daniels,Suta, Krista,Turks, Maris
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supporting information
p. 1414 - 1419
(2016/03/19)
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- An efficient and convenient synthesis of N-substituted amides under heterogeneous condition using Al(HSO4)3 via Ritter reaction
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An efficient and inexpensive synthesis of N-substituted amides from the reaction of aliphatic and aromatic nitriles with various benzylic alcohols (secondary and tertiary) and tert-butyl alcohol by refluxing nitromethane via the Ritter reaction catalyzed by aluminum hydrogen sulfate [Al(HSO4)3] is described. The catalyst which is an air-stable, cost-effective solid acid could be readily recycled by filtration and reused four times without any significant loss of its activity. [Figure not available: see fulltext.]
- Karimian, Elnaz,Akhlaghinia, Batool,Ghodsinia, Sara S.E.
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p. 429 - 439
(2016/03/16)
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- Mechanochemical ritter reaction: A rapid approach to functionalized amides at room temperature
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A fast and efficient mechanochemical Ritter reaction between alcohols and nitriles under mild conditions is demonstrated. The reaction proceeds rapidly at room temperature in a solvent-free or low-solvent environment by using a Br?nsted acid catalyst. Its general application has been verified through a substrate screening comprising a wide range of functionalized nitriles as well as secondary and tertiary alcohols. Gentle Ritter: A fast and efficient mechanochemical Ritter reaction under mild conditions is described. The reaction proceeds rapidly at room temperature in a solvent-free or low-solvent environment by using sulfuric acid as catalyst.
- Dokli, Irena,Gredi?ak, Matija
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supporting information
p. 2727 - 2732
(2015/04/27)
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- An organocatalytic biomimetic approach to α-aminophosphonates
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A novel biomimetic approach to optically active α-aminophosphonates utilizing readily available acylphosphonates and 2-chlorobenzylamine as starting materials has been described. The enantioselective protonation constitutes the main enantiodifferentiating step in the developed strategy. This nature-inspired approach proceeds efficiently and in a highly stereoselective manner. This journal is
- Kowalczyk, Dorota,Albrecht, Lukasz
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supporting information
p. 3981 - 3984
(2015/03/30)
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- Microwave assisted, Ca(II)-catalyzed Ritter reaction for the green synthesis of amides
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An efficient solvent-free synthesis of amides by Ca(II) catalyzed Ritter reaction has been reported under microwave irradiation. This green protocol tolerates the substrate diversity and delivers the high yielding amides with minimal loading of inexpensive and more abundant Ca(II) catalyst.
- Yaragorla, Srinivasarao,Singh, Garima,Lal Saini, Pyare,Reddy, M. Kesava
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p. 4657 - 4660
(2014/12/10)
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- Magnetic CoFe2O4 nanoparticle immobilized N-propyl diethylenetriamine sulfamic acid as an efficient and recyclable catalyst for the synthesis of amides via the Ritter reaction
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A magnetic CoFe2O4 nanoparticle immobilized diamine-N-sulfamic acid (CoFe2O4@SiO2-DASA) was synthesized and used as efficient heterogeneous catalyst for the synthesis of amides via the Ritter reaction under solvent-free conditions. The magnetic nanocatalyst could be readily recovered by applying an external magnet and recycled several times without considerable loss of its catalytic activity.
- Zhao, Xiao-Na,Hu, Hai-Chuan,Zhang, Fu-Jun,Zhang, Zhan-Hui
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p. 258 - 265
(2014/07/08)
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- Gold-catalyzed 1,2-oxoarylations of nitriles with pyridine-derived oxides
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We report the first success in the gold-catalyzed oxoarylations of nitriles with pyridine-derived N-oxides using gold carbenes as initiators. These oxoarylations were also achieved satisfactorily in intermolecular three-component oxidations, including diverse alkenyldiazo esters, nitriles, and pyridine-based oxides. Spill the (car)benes: Reported herein is the first successful gold-catalyzed oxoarylation of nitriles with pyridine-derived N-oxides using gold carbenes as initiators (see scheme; DCE=1,2-dichloroethane, IPr=1,3-bis(diisopropylphenyl)imidazol-2-ylidene). These oxoarylations were also achieved satisfactorily in intermolecular three-component oxidations using a variety of alkenyldiazo esters, nitriles, and pyridine-based N-oxides.
- Karad, Somnath Narayan,Liu, Rai-Shung
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supporting information
p. 5444 - 5448
(2014/06/09)
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- A Lewis acid palladium(II)-catalyzed three-component synthesis of α-substituted amides
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A Lewis acid palladium-catalyzed reaction of amides, aryl aldehydes, and arylboronic acids is described. This new method allows for a practical and general synthesis of α-substituted amides from simple, readily available building blocks.
- Beisel, Tamara,Manolikakes, Georg
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supporting information
p. 6046 - 6049
(2014/01/06)
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- Catalytic properties and acidity of 1,2-benzenedisulfonimide and some of its derivatives. An experimental and computational study
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1,2-Benzenedisulfonimide (1) has previously been found to be an excellent and, importantly, safe Br?nsted acid catalyst. In this work we present the results of a search for derivatives of 1 that are more acidic and effective. Instead of blindly synthesizing a series of analogues, we have carried out a screening process in which the pKa of 1 and a set of its derivatives were calculated. The calculated pKa values were confirmed experimentally by carrying out determination through potentiometric titrations of some of the compounds: 1, 4-methyl and 4-nitro derivatives of 1. The calculations indicated that the dinitro and 4-nitro derivatives are among the best candidates for the synthesis. The latter was obtained in good yields and tested as a catalyst. Results were excellent as the reactions took place more quickly and at lower temperatures in all cases, and in a number of cases it was even possible to reduce the amount of catalyst.
- Barbero, Margherita,Berto, Silvia,Cadamuro, Silvano,Daniele, Pier Giuseppe,Dughera, Stefano,Ghigo, Giovanni
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p. 3212 - 3217
(2013/04/24)
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- Ritter reactions between alcohols and acetonitrile mediated by the conducting polymer poly-(3,4-ethylenedioxy thiophene) (Pedot)
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Herein, we report new reactivity of the conducting polymer, poly-(3,4-ethylenedioxy thiophene) (PEDOT), where PEDOT mediates a Ritter reaction between alcohols and acetonitrile. The yields were variable and in most cases competitive with results obtained using sulfuric acid. Attempts at a stoichiometric reaction between benzonitrile and diphenylmethanol are also reported herein. Finally, described here are preliminary mechanistic studies that suggest PEDOT is behaving as an alcohol-selective or specific Lewis acid. Taylor & Francis Group, LLC.
- D-Angelo, John G.,Cody, Jeremy A.,Larrabee, Christian,Ostrander, Danica J.,Rugg, Kyle W.,Mamangun, Donna
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supporting information
p. 3224 - 3232
(2014/01/06)
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- Electron transfer in the peroxytrifluoroacetic acid-assisted sulfoxidation and oxidative destruction of benzhydryl sulfides
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The reactions of benzhydryl sulfides Ph2CHSCH2R (R = H, CONH2, COOH, CN) with peroxytrifluoroacetic acid in CF 3COOH were studied experimentally and by the quantum chemical density functional theory (DFT) method and exhibited an unusual dependence on the substituent R. When R≠H, a complicated oxidative destruction of the substrates occurs to form 2,4,6-tribenzhydrylphenol as one of the products, while in the case of R = H, the starting benzhydryl sulfide is smoothly sulfoxidated. This fact is due to the common electron transfer from the substrate to reagent at the initial step and the difference in subsequent transformations of the species formed.
- Akopova,Morkovnik,Khrustalev,Bicherov
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p. 1164 - 1175
(2014/03/21)
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- Aluminum triflate as a powerful catalyst for direct amination of alcohols, including electron-withdrawing group-substituted benzhydrols
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Direct aminations of allylic alcohols, benzylic alcohols, and benzhydrols with electron-withdrawing (F, Br, I, NO2, or CN) substituents were efficiently catalyzed by aluminum triflate [Al(OTf)3] to afford the corresponding biarylamines in high yield, and the dibromo-substituted product was further transformed into letrozole. Copyright
- Ohshima, Takashi,Ipposhi, Junji,Nakahara, Yasuhito,Shibuya, Ryozo,Mashima, Kazushi
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supporting information
p. 2447 - 2452
(2012/11/07)
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- Preparation of different amides via Ritter reaction from alcohols and nitriles in the presence of silica-bonded N-propyl sulphamic acid (SBNPSA) under solvent-free conditions
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A number of methods have been proposed for the modification of the Ritter reaction. However, many of these methods involve the use of strongly acidic conditions, stoichiometric amounts of reagents, harsh reaction conditions and extended reaction times. Th
- Shakeri, Maryam-Sadat,Tajik, Hassan,Niknam, Khodabakhsh
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p. 1025 - 1032
(2013/03/14)
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- Ritter reactions in flow
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Flow me a Ritter: Ritter reactions are performed in a simple microreactor setup using tert-butylacetate as versatile carbocation source. The protocol avoids the handling of large amounts of hot concentrated sulfuric acid as low concentrations are optimal for rapid access tert-butyl- or diphenylmethyl- protected amides. Copyright
- Audiger, Logan,Watts, Kevin,Elmore, Simon C.,Robinson, Richard I.,Wirth, Thomas
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experimental part
p. 257 - 260
(2012/05/04)
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- Ritter reaction in subcritical water: An efficient and green method for amides synthesis
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Ritter reaction was carried out efficiently in subcritical water with catalytic amount of trifluoromethanesulfonic acid. The amides were formed in good to excellent yields from secondary alcohols and tert-butanol with various nitriles.
- Jiang, Shengqian,Wang, Zhouyu,Jiang, Zhenju,Li, Jianhui,Zhou, Shulin,Pu, Long
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experimental part
p. 24 - 28
(2012/08/08)
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- Electrochemical oxidation of amides of type Ph2CHCONHAr
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Anodic oxidation of N-aryl-2,2-diphenylacetamides in acetonitrile undergoes three types of bond-cleavage, one between the benzylic carbon and the carbonyl group, the second between a carbonyl and 'N', and the third between the 'N' atom and aryl group. The selectivity of the cleavage and nature of emerged products is highly dependent on the nature of substituent attached to the aryl group. For example, electron-withdrawing groups direct the benzyl-carbonyl bond-breaking whereas electron-donating substituents favor the N-aryl bond cleavage. The type of products obtained involve benzophenone, 2,2-diphenylacetamide, N-(diphenylmethylene)acetamide, N-(diphenylmethyl)acetamide, α-lactam (1-acetyl-3,3-diphenylaziridin-2-one, as a 1:1 complex with 2,4-dinitroaniline) and aniline derivatives.
- Golub, Tatiana,Becker, James Y.
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experimental part
p. 3906 - 3912
(2012/06/04)
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- Gold catalysis: Alkyl migration in the addition of alcohols to nitriles
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Benzhydroles and nitriles upon gold-catalysed conversion deliver symmetrical ethers and/or N-substituted carboxylic amides. While with most phosphane ligands tested, the dominating product is always the ether, with the trimesitylene ligand the amides are the major products. The reaction conditions are much milder than those reported previously. Mechanistic control experiments with a chiral alcohol prove the intermediacy of carbenium ions, further studies with not readily ionisable alcohols indicate that for the benzhydroles the carbenium ions and gold(I)-hydroxy complexes are intermediates.
- Ibrahim, Nada,Hashmi, A. Stephen K.,Rominger, Frank
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scheme or table
p. 461 - 468
(2011/04/16)
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- Efficient dehydrative C-N bond formation using alcohols and amides in the presence of silica supported perchloric acid as a heterogeneous catalyst
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Silica supported perchloric acid has been utilized as an efficient heterogeneous recyclable catalyst for N-alkylation of amides (sulfonamides and carboxamides) using alcohols (primary and secondary aliphatic as well as benzylic). The products are formed in high yields within 2-3 h.
- Das, Biswanath,Reddy, Parigi Raghavendar,Sudhakar, Chithaluri,Lingaiah, Maram
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experimental part
p. 3521 - 3522
(2011/06/27)
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- Organocatalytic synthesis of amides from nitriles via the Ritter reaction
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A simple, inexpensive, environmentally friendly, and efficient route for the synthesis of a wide variety of amides in high yields via the Ritter reaction of alcohols with nitriles has been demonstrated. Pentafluorophenyl ammonium triflate (PFPAT) is used as an organocatalyst and is air-stable, cost-effective, easy to handle, and easily removed from the reaction mixtures.
- Khaksar, Samad,Fattahi, Eskandar,Fattahi, Esmail
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experimental part
p. 5943 - 5946
(2011/11/28)
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- Silica boron-sulfuric acid nanoparticles (SBSANs): Preparation, characterization and their catalytic application in the Ritter reaction for the synthesis of amide derivatives
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Among a number of different heterogeneous and homogeneous catalysts, silica boron-sulfuric acid nanoparticles (SBSANs) with both protic and Lewis acidic sites were shown to be the most active and recyclable catalyst in the Ritter reaction. Various amide d
- Khalafi-Nezhad, Ali,Foroughi, Habib Ollah,Doroodmand, Mohammad Mahdi,Panahi, Farhad
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experimental part
p. 12842 - 12851
(2012/01/14)
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- Sulfated tungstate: An efficient catalyst for the Ritter reaction
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The use of sulfated tungstate as an efficient and reusable catalyst for the preparation of amides from alcohols and nitriles via the Ritter reaction pathway is discussed. The reaction proceeds under solvent free conditions. The Royal Society of Chemistry.
- Katkar, Kamlesh V.,Chaudhari, Pramod S.,Akamanchi, Krishnacharya G.
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supporting information; experimental part
p. 835 - 838
(2011/05/15)
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- Halogen-bond-induced activation of a carbon-heteroatom bond
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Benzhydryl bromide can be activated by novel halogen-bond donors and subsequently undergoes a Ritter-like reaction with acetonitrile (see scheme). Comparative experiments with non-iodinated reference compounds and tests with added acids indicate that halo
- Walter, Sebastian M.,Kniep, Florian,Herdtweck, Eberhardt,Huber, Stefan M.
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supporting information; experimental part
p. 7187 - 7191
(2011/09/16)
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- Amberlyst-15 in ionic liquid: An efficient and recyclable reagent for nucleophilic substitution of alcohols and hydroamination of alkenes
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The nucleophilic substitution reaction of secondary alcohols and hydroamination of alkenes with amides, sulfonamides, carbamates, and amines using Amberlyst-15 immobilized in [Bmim][BF4] (1-butyl-3- methylimidazolium tetrafluoroborate) ionic liquid as an efficient recyclable reagent is described. The solvent effect is prominent in the reaction, and the desired substitution products are obtained in good to excellent yield. The protocol is advantageous due to the ease of handling of the reagents, the simple work-up procedure, and the environmentally benign conditions that allow effective recyclability. A facile protocol involving Amberlyst-15 in the ionic liquid [Bmim][BF4] (= 1-butyl-3-methylimidazolium tetrafluoroborate) has been developed for nucleophilic substitution of alcohols and hydroamination of alkenes.
- Qureshi, Ziyauddin S.,Deshmukh, Krishna M.,Tambade, Pawan J.,Dhake, Kishor P.,Bhanage, Bhalchandra M.
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experimental part
p. 6233 - 6238
(2010/12/25)
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- The Ritter reaction under incredibly green protocol: Nano magnetically silica-supported Br?nsted acid catalyst
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HClO4-functionalized silica-coated magnetic nanoparticles [γ-Fe2O3@SiO2-HClO4] (2.5 mol%) has been found to be a capable biocompatible and recyclable catalyst for highly efficient conversion of a variety of alcohols to corresponding amides via modified Ritter reaction in good to excellent yields. Since this heterogeneous catalyst can be simply removed by using an external magnetic device then recovered, it also enhances product purity and promises economic.
- Ma'mani, Leila,Heydari, Akbar,Sheykhan, Mehdi
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experimental part
p. 122 - 127
(2010/11/04)
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- Iodine-catalyzed one-pot synthesis of amides from nitriles via Ritter reaction
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Ritter reactions of alcohols and tert-butyl acetate with various nitriles were performed using iodine as a mild and effective catalyst under heating conditions to afford the corresponding amides in good to excellent yields.
- Theerthagiri, Palani,Lalitha, Appaswami,Arunachalam, Pirama Nayagam
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supporting information; experimental part
p. 2813 - 2819
(2010/07/04)
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- o-Benzenedisulfonimide as a reusable Bronsted acid catalyst for Ritter-type reactions
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Reactions between various benzyl alcohols or tert-butyl alcohol and nitriles were carried out in the presence of catalytic amounts (usually 10-20 mol-%) of o-benzenedisulfonimide as a Bronsted acid catalyst; the reaction conditions were mild and the yields of amides were good. The catalyst was easily recovered and purified, ready to be used in further reactions, with economic and ecological advantages. Wiley-VCH Verlag GmbH & Co. KGaA, 2009.
- Barbero, Margherita,Bazzi, Stefano,Cadamuro, Silvano,Dughera, Stefano
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experimental part
p. 430 - 436
(2009/07/19)
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- FeCl3-catalyzed Ritter reaction. Synthesis of amides
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A safe and inexpensive synthesis of amides, from benzylic alcohols and nitriles and from t-butyl acetate and nitriles, using a Ritter reaction catalyzed by FeCl3·6H2O is described.
- Anxionnat, Bruno,Guérinot, Amandine,Reymond, Sébastien,Cossy, Janine
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experimental part
p. 3470 - 3473
(2009/09/28)
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- Polyvinylpolypyrrolidone-supported boron trifluoride: A high-loaded, polymer-supported Lewis acid for the Ritter reaction
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A Mild and efficient method for preparing amides by reaction of nitriles with benzhydrol and tertiary alcohols is described using polyvinylpolypyrrolidone-supported boron trifluoride. Selective amidation of benzhydrol in the presence of primary benzyl alcohols was also achieved.
- Lakouraj, Moslem Mansour,Mokhtary, Masoud
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experimental part
p. 53 - 56
(2010/03/30)
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- α-Amidobenzylation of aryl and alkenyl halides via palladium-catalyzed Suzuki-Miyaura coupling with α-(acylamino) benzylboronic esters
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The Suzuki-Miyaura coupling of α-(acetylamino)benzylboronic esters with aryl and alkenyl halides has been achieved using a Pd/P(t-Bu)3 catalyst with KF and H2O in 1,4-dioxane, giving α-substituted benzylamines in high yields. Copyright
- Ohmura, Toshimichi,Awano, Tomotsugu,Suginome, Michinori
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p. 664 - 665
(2011/04/22)
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- An efficient FeCl3-catalyzed amidation reaction of secondary benzylic and allylic alcohols with carboxamides or p-toluenesulfonamide
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A simple, inexpensive, environmentally friendly and high yielding amidation reaction of benzylic and allylic alcohols with primary amides using a catalytic amount of FeCl3 (5 mol %) is described. Direct substitution of various amides such as be
- Jana, Umasish,Maiti, Sukhendu,Biswas, Srijit
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p. 858 - 862
(2008/04/13)
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- Photosensitized electron transfer oxidation of sulfides: A steady-state study
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The photosensitized electron-transfer oxidation of a series of ethyl sulfides RSEt (1, R = C12H25; 2, PhCH2CH 2; 3, PhCH2; 4, PhCMe2; 5, Ph2CH) has been examined in acetonitrile and the product distribution discussed on the basis of the mechanisms proposed. In nitrogen-flushed solutions, cleaved alcohols and alkenes are formed, whereas under oxygen, in reactions that are 10-70 times faster, sulfoxides and cleaved aldehydes and ketones are formed in addition to the afore-mentioned products. Two sensitizers are compared, 9,10-dicyanoanthracene (DCA) and 2,4,6-triphenylpyrylium tetrafluoroborate (TPP+BF4-), the former giving a higher proportion of the sulfoxide, the latter of cleaved carbonyls. The sulfoxidation is due to the contribution of the singlet oxygen path with DCA. Oxidative cleavage, on the other hand, occurs both with DCA and with TPP+ which is known to produce neither singlet oxygen nor the superoxide anion. This process involves deprotonation from the α position of the sulfide radical cation, but the TPP+ results suggest that O2.- is not necessarily involved and non-activated oxygen forms a weak adduct with the radical cation promoting α-hydrogen transfer, particularly with benzylic derivatives. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Bonesi, Sergio M.,Fagnoni, Maurizio,Albini, Angelo
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scheme or table
p. 2612 - 2620
(2009/04/05)
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- (P2O5/SiO2): a useful heterogeneous alternative for the Ritter reaction
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Tertiary alcohols as well as primary and secondary benzylic alcohols react efficiently with nitriles to give the corresponding amides in good to excellent yields in the presence of P2O5/SiO2 (60% w/w).
- Tamaddon, Fatemeh,Khoobi, Mehdi,Keshavarz, Elham
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p. 3643 - 3646
(2008/02/03)
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- New boron(III)-catalyzed amide and ester condensation reactions
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In 1996, we reported that benzeneboronic acids bearing electron-withdrawing groups at the meta- or para-position are highly effective catalysts for the amide condensation reaction in less-polar solvents. In this paper, we report that N-alkyl-4-boronopyridinium halides are more effective catalysts than the previous ones in more polar solvents. N-Alkyl-4-boronopyridinium halides are effective not only for amide condensation between equimolar mixtures of carboxylic acids and amines but also for the esterification of α-hydroxycarboxylic acids in alcohol solvents. Furthermore, perchlorocatecholborane is more effective than areneboronic acids for the amide condensation of sterically demanding carboxylic acids. In addition, Lewis acid-assisted Br?nsted acid (LBA), which is prepared from a 1:2 M mixture of boric acid and tetrachlorocatechol, is effective for the Ritter reaction from alcohols and nitriles to amides.
- Maki, Toshikatsu,Ishihara, Kazuaki,Yamamoto, Hisashi
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p. 8645 - 8657
(2008/02/08)
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