- Pd-Catalyzed Oxidative Aminocarbonylation of Arylboronic Acids with Unreactive Tertiary Amines via C-N Bond Activation
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An efficient synthesis of tertiary amides from aryl boronic acids and inert tertiary amines through the oxidative carbonylation via C(sp3)-N bond activation is presented. This protocol significantly restricts the homocoupling biarylketone product. It involves the use of a homogeneous PdCl2/CuI catalyst and a heterogeneous Pd/C based catalyst, which promotes C(sp3)-N bond activation of tertiary amines with aryl boronic acids. This process represents a ligand-free, base-free, and recyclable catalyst along with an ideal oxidant like molecular oxygen.
- Kolekar, Yuvraj A.,Bhanage, Bhalchandra M.
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p. 14028 - 14035
(2021/05/29)
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- Highly Chemoselective Deoxygenation of N-Heterocyclic N-Oxides Using Hantzsch Esters as Mild Reducing Agents
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Herein, we disclose a highly chemoselective room-temperature deoxygenation method applicable to various functionalized N-heterocyclic N-oxides via visible light-mediated metallaphotoredox catalysis using Hantzsch esters as the sole stoichiometric reductant. Despite the feasibility of catalyst-free conditions, most of these deoxygenations can be completed within a few minutes using only a tiny amount of a catalyst. This technology also allows for multigram-scale reactions even with an extremely low catalyst loading of 0.01 mol %. The scope of this scalable and operationally convenient protocol encompasses a wide range of functional groups, such as amides, carbamates, esters, ketones, nitrile groups, nitro groups, and halogens, which provide access to the corresponding deoxygenated N-heterocycles in good to excellent yields (an average of an 86.8% yield for a total of 45 examples).
- An, Ju Hyeon,Kim, Kyu Dong,Lee, Jun Hee
-
supporting information
p. 2876 - 2894
(2021/02/01)
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- A predictive model for additions to: N -alkyl pyridiniums
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Disclosed in this communication is a thorough study on the dearomative addition of organomagnesium nucleophiles to N-alkyl pyridinium electrophiles. The regiochemical outcomes have observable and predictable trends associated with the substituent patterns on the pyridinium electrophile. Often, the substituent effects can be either additive, giving high selectivities, or ablative, giving competing outcomes. Additionally, the nature of the organometallic nucleophilic component was also investigated for its role in the regioselective outcome. The effects of either reactive component are important to both the overall reactivity and site of nucleophilic addition. The utility of these observed trends is demonstrated in a concise, dearomative synthesis of a tricyclic compound shown to have insecticidal activity. This journal is
- Knight, Brian J.,Tolchin, Zachary A.,Smith, Joel M.
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supporting information
p. 2693 - 2696
(2021/03/18)
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- Direct Amidation of Esters by Ball Milling**
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The direct mechanochemical amidation of esters by ball milling is described. The operationally simple procedure requires an ester, an amine, and substoichiometric KOtBu and was used to prepare a large and diverse library of 78 amide structures with modest to excellent efficiency. Heteroaromatic and heterocyclic components are specifically shown to be amenable to this mechanochemical protocol. This direct synthesis platform has been applied to the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals as well as the gram-scale synthesis of an active pharmaceutical, all in the absence of a reaction solvent.
- Barreteau, Fabien,Battilocchio, Claudio,Browne, Duncan L.,Godineau, Edouard,Leitch, Jamie A.,Nicholson, William I.,Payne, Riley,Priestley, Ian
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supporting information
p. 21868 - 21874
(2021/09/02)
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- Photorelease of Pyridines Using a Metal-Free Photoremovable Protecting Group
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The photorelease of bioactive molecules has emerged as a valuable tool in biochemistry. Nevertheless, many important bioactive molecules, such as pyridine derivatives, cannot benefit from currently available organic photoremovable protecting groups (PPGs). We found that the inefficient photorelease of pyridines is attributed to intramolecular photoinduced electron transfer (PET) from PPGs to pyridinium ions. To alleviate PET, we rationally designed a strategy to drive the excited state of PPG from S1 to T1 with a heavy atom, and synthesized a new PPG by substitution of the H atom at the 3-position of 7-dietheylamino-coumarin-4-methyl (DEACM) with Br or I. This resulted in an improved photolytic efficiency of the pyridinium ion by hundreds-fold in aqueous solution. The PPG can be applied to various pyridine derivatives. The successful photorelease of a microtubule inhibitor, indibulin, in living cells was demonstrated for the potential application of this strategy in biochemical research.
- Dong, Zaizai,Fang, Xiaohong,Kou, Xiaolong,Tan, Weihong,Tang, Xiao-Jun,Wu, Yayun,Zhang, Zhen,Zhao, Rong,Zhou, Wei
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supporting information
p. 18386 - 18389
(2020/08/24)
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- Palladium nanoparticles on a pyridinium supported ionic liquid phase: a recyclable and low-leaching palladium catalyst for aminocarbonylation reactions
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A new SILP (Supported Ionic Liquid Phase) palladium catalyst was prepared and characterized by 13C and 29Si CP MAS NMR, DTG, FTIR and TEM. The presence of the grafted pyridinium cations on the surface of the support was found to result in the formation of highly dispersed Pd nanoparticles with their diameter in the range of 1-2 nm. The catalyst was proved to be active not only in the aminocarbonylation of some model compounds but also in the synthesis of active pharmaceutical ingredients. Catalyst recycling and palladium leaching studies were carried out for the first time in aminocarbonylations leading to CX-546(1-(1,4-benzodioxan-6-ylcarbonyl)piperidine), Moclobemide, Nikethamide and a precursor of Finasteride. The latter reaction proves that not only aryl iodides but also an iodoalkene can be converted into the products with the help of the heterogeneous catalyst. The results show that the conditions should be always fine-tuned in the reactions of different substrates to achieve optimal results. Palladium loss was also observed to depend considerably on the nature of the reaction partners. This journal is
- Adamcsik, Bernadett,Nagy, Enik?,Pekker, Péter,Skoda-F?ldes, Rita,Szabó, Péter,Urbán, Béla
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p. 23988 - 23998
(2020/07/14)
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- Pd/PTABS: An Efficient Catalytic System for the Aminocarbonylation of a Sugar-Protected Nucleoside
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A highly efficient and mild protocol for the aminocarbonylation of a nucleoside is developed by employing palladium/(1,3,5-Triaza-7-phosphaadamantan-1-ium-1-yl)butane-1-sulfonate (Pd/PTABS) as the catalytic system. The developed aminocarbonylation methodology employs CO gas at a relatively low temperature of 60? °C and is suitable for a wide range of amines, including (heteroaryl)benzylic, aliphatic acyclic, alicyclic and secondary amines. This protocol is also utilized for the synthesis of a sangivamycin precursor by carrying out the Pd-catalyzed amination and aminocarbonylation simultaneously. The utility of this protocol is further demonstrated by the synthesis of the drugs moclobemide and nikethamide.
- Bhanage, Bhalchandra M.,Bhilare, Shatrughn,Gaikwad, Vinayak,Gupta, Gaurav,Kapdi, Anant R.,Sanghvi, Yogesh S.,Shah, Jagrut
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supporting information
p. 4239 - 4248
(2019/11/14)
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- COtab: Expedient and Safe Setup for Pd-Catalyzed Carbonylation Chemistry
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Bench-stable tablets (COtabs) have been developed for the rapid and safe production of carbon monoxide. The tablets can be made in less than 5 min without the use of a glovebox and only require a stock solution of an amine base to liberate a specific quantity of CO in a two-chamber system. The COtabs were tested in five different carbonylation reactions and provided similar yields compared to literature procedures. Finally, a gram-scale reaction was conducted, as well as 13C-isotope labeling of the anticancer drug, olaparib.
- Collin, Hugo P.,Reis, Wallace J.,Nielsen, Dennis U.,Lindhardt, Anders T.,Valle, Marcelo S.,Freitas, Rossimiriam P.,Skrydstrup, Troels
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supporting information
p. 5775 - 5778
(2019/08/26)
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- Method for preparing nikethamide
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The invention relates to a method for preparing nikethamide. The method for preparing nikethamide comprises the following steps: S1, a certain amount of a solvent and a certain amount of niacin are added into a reaction bottle, mixing and stirring are carried out for 30-40 minutes, and the materials are cooled to the room temperature; S2, a certain amount of organic amine is added dropwisely withstirring in order to slowly increase the temperature of the reaction mixture system; S3, when the temperature of the system is raised to 70-80 DEG C, a certain amount of a by-product inhibitor and a mixed solution A are added dropwisely, and after the dropwise addition is completed, the reaction system is heated for reflux for 30 min; S4, the materials are continued to stir and cooled to the roomtemperature, a certain amount of sodium hydroxide solution is added dropwisely till the pH value of a water layer is about 8-9, an organic layer is separated, the water layer is extracted twice with trichloroethane, the organic layer is combined, concentration and reduced pressure distillation are carried out, and the product nikethamide is collected. The method for preparing nikethamide has the advantages of high product yield, few by-products, and easy treatment; and compared with other methods, the method is more environmentally friendly.
- -
-
Paragraph 0027-0047
(2018/11/03)
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- Metal-Free Amidation of Acids with Formamides and T3P
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A new, simple and metal-free method for the direct formation of dialkylamides from carboxylic acids employing N,N-dialkylformamides as amine source is described. The one-pot reaction is promoted by propylphosphonic anhydride (T3P) in the presence of 0.5 equivalents of HCl.
- Bannwart, Linda,Abele, Stefan,Tortoioli, Simone
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p. 2069 - 2078
(2016/07/06)
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- Chloroform as a Carbon Monoxide Precursor: In or Ex Situ Generation of CO for Pd-Catalyzed Aminocarbonylations
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Conditions for the rapid hydrolysis of chloroform to carbon monoxide (CO) using heterogeneous CsOH·H2O are described. CO and 13CO can be generated cleanly and rapidly under mild conditions and can be captured either in or ex situ in palladium-catalyzed aminocarbonylation reactions. Utilizing only 1-3 equiv of CO allows for the aminocarbonylation of aryl, vinyl, and benzyl halides with a wide variety of primary and secondary amines giving amide products in good to excellent yields. (Chemical Equation Presented).
- Gockel, Samuel N.,Hull, Kami L.
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supporting information
p. 3236 - 3239
(2015/07/15)
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- C-H activation by amide chelation control: Ruthenium-catalyzed direct synthesis of 2-Aryl-3-furanamides
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A new, catalytic methodology for the synthesis of heterobiaryls by the ruthenium-catalyzed C-H activation/cross-coupling of heterocyclic amides with aryl boroneopentylates is surveyed. From this survey, the highly regioselective reaction of furan-3-carboxamide to give 2-aryl-3-furanamides is optimized and generalized in scope with respect to the aryl boroneopentylate coupling partners. Established thereby is a one-step synthetic method which may supercede the broadly applied two-step directed ortho metalation (DoM)-cross coupling reaction involving cryogenic and strong base conditions and which has potential for further ortho and remote metalation chemistry.
- Zhao, Yigang,Snieckus, Victor
-
supporting information
p. 1527 - 1532
(2014/06/09)
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- Palladium nanoparticles supported on ZIF-8 as an efficient heterogeneous catalyst for aminocarbonylation
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Pd nanoparticles supported on ZIF-8 (PdNPs/ZIF-8) are described as an efficient heterogeneous catalyst for the aminocarbonylation of bromoarenes in the presence of phosphines and iodoarenes under phosphine-free conditions. The catalyst can be readily prepared and is air-stable. The palladium loading can be as low as 1 wt %, and the catalyst was recycled four times with negligible change in catalytic performance. A variety of pharmaceutically important amides was readily synthesized. A TON of 2540 was easily achieved in a batch reaction by scaling up to a gram scale. The catalyst reported can also be applied to the synthesis of cyclic and primary amides as well as an alkoxycarbonylation reaction to form an ester.
- Dang, Tuan T.,Zhu, Yinghuai,Ngiam, Joyce S. Y.,Ghosh, Subhash C.,Chen, Anqi,Seayad, Abdul M.
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p. 1406 - 1410
(2013/07/26)
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- Continuous Method For Producing Amides Of Aromatic Carboxylic Acids
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The invention relates to a continuous method for producing amides of aromatic carboxylic acids by reacting at least one carbonic acid ester of formula (I) R3—OOOR4, wherein R3 represents an optionally substituted aromatic hydrocarbon group with 5 to 100 carbon atoms and R4 represents a hydrocarbon group with 1 to 30 carbon atoms, with at least one amine of formula (II) HNR1R2, wherein R1 and R2 independently represent hydrogen or a hydrocarbon group with 1 to 100 C atoms, in a reaction tube the longitudinal axis of which extends in the direction of propagation of the microwaves of a monomode microwave applicator, under microwave irradiation to form carboxamide.
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Page/Page column 9
(2012/04/23)
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- Chemistry of heteroaryltriphenylphosphonium iodides: Preparation from iodoheteroaromatics and elimination of the phosphonium iodide group using basic solvents
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α- and γ-Iodoheteroaromatics were found to react with triphenylphosphine to give heteroaromatictriphenylphosphonium iodides in excellent yields, β-lodoheteroaromatics, which are less reactive with triphenylphosphine compared to α- or γ-compounds, were con
- Sato, Akihiro,Sugimoto, Osamu,Tanji, Ken-ichi
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experimental part
p. 2735 - 2739
(2010/04/25)
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- Silica-supported 2,4,6-trichloro-1,3,5-triazine as an efficient reagent for direct conversion of carboxylic acids to amides under solvent-free conditions
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A very simple and efficient solvent-free method for the direct conversion of carboxylic acids to primary, secondary, tertiary alkyl, and aromatic amides in the presence of the corresponding ammonium salts, silica-supported 2,4,6-trichloro-1,3,5-triazine, and triethylamine is described. The reactions proceed rapidly at room temperature, and the products are obtained in moderate to excellent yields. Copyright Taylor & Francis Group, LLC.
- Khalafi-Nezhad, Ali,Zare, Abdolkarim,Parhami, Abolfath,Rad, Mohammad Navid Soltani,Nejabat, Gholam Reza
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p. 657 - 666
(2008/09/21)
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- Efficient method for the direct preparation of amides from carboxylic acids using tosyl chloride under solvent-free conditions
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A simple, clean and highly efficient solvent-free procedure for the preparation of primary, secondary, tertiary and aromatic amides is described from the direct reaction of carboxylic acids and silica-supported ammonium salts, triethylamine (TEA) and tosyl chloride (TsCl) as condensing agent. The reaction proceeds rapidly in high yields at room temperature.
- Khalafi-Nezhad, Ali,Parhami, Abolfath,Soltani Rad, Mohammad Navid,Zarea, Abdolkarim
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p. 6879 - 6882
(2007/10/03)
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- Method for the synthesis of amides and related products from esters or ester-like compounds
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A versatile, eco-friendly, and efficient method for the convenient conversion of esters and ester-like compounds into amides, peptides, carbamates, ureas, oxamides, oxamates, hydrazides, oxazolidinones, pyrazolones, oxazolidinediones, barbituric acids, and other molecules containing one or more OCN moieties in the presence of a diol or polyol is disclosed.
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Page/Page column 11
(2008/06/13)
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- Synthesis of substituted aryl amidines from aminoacetonitriles
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Aryl aminoacetonitriles are oxidized by NiO2-H2O or MnO2 in the presence of a wide range of NH2-containing compounds to afford aryl amidines, presumably via iminium intermediates. A 'one-pot' procedure for the preparation of heteroaryl amidines from N-containing heteroaryl halides through a process comprising sequential SNAr substitution and oxidation has also been developed.
- Yin, Zhiwei,Zhang, Zhongxing,Zhu, Juliang,Wong, Henry,Kadow, John F.,Meanwell, Nicholas A.,Wang, Tao
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p. 4919 - 4923
(2007/10/03)
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- Method of inhibiting angiogenesis
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Compounds having the formula are angiogenesis inhibitors. Also disclosed are compositions containing the compounds, methods of making the compounds, and methods of treatment using the compounds.
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Page/Page column 10
(2008/06/13)
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- Method of inhibiting angiogenesis
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Compounds having the formula are angiogenesis inhibitors. Also disclosed are compositions containing the compounds, methods of making the compounds, and methods of treatment using the compounds.
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- Niobium pentachloride promoted conversion of carboxylic acids to carboxamides: Synthesis of the 4-aryl-1,2,3,4-tetrahydroisoquinoline alkaloid structures
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A practical method for the conversion of carboxylic acids to the corresponding carboxamides mediated by niobium pentachloride under mild conditions is described. The synthesis of the 4-aryl-1,2,3,4-tetrahydroisoquinoline alkaloid structures was accomplished via benzylic lithiation of N-methyl-3,4-dimethoxy-2-(4′-methoxybenzyl)benzamide.
- Nery, Marcelo S.,Ribeiro, Renata P.,Lopes, Claudio C.,Lopes, Rosangela S. C.
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p. 272 - 276
(2007/10/03)
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- Double carbonylation of aryl iodides with diethylamine catalyzed by dinuclear palladium complexes
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Dinuclear palladium complexes bridged by a novel PNNP ligand, N,N ′-bis[(2-diphenylphosphino)phenylformamidinate (dpfam), were found to be very efficient and selective catalysts for the double carbonylation of iodobenzene with diethylamine using K3PO4 as base and 1,4-dioxane as solvent with a TON up to 105 and selectivity of 96%.
- Tsukada, Naofumi,Ohba, Yoichi,Inoue, Yoshio
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p. 436 - 443
(2007/10/03)
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- Molecular Determinants of the Platelet Aggregation Inhibitory Activity of Carbamoylpiperidines
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A series of α,α'-bis-p-xylenes were synthesized and tested for their inhibitory activity on ADP-induced aggregation of human platelets.A parabolic curve was obtained when log 1/C (activity) was plotted against log P (octanol/water partition coefficient).Using this as a model, a new analogue, α,α'-bis-p-xylene (3g), was synthesized with a predicted IC50 of 25 μM.When this compound was subsequently evaluated, the IC50 was 22.1 +/- 5.5 μM, demonstrating the applicability of this model.The amide oxygen of the carbamoyl substituent appeared necessary for activity.Thus, for example, when the amide carbonyl group of 3a (IC50 = 44.5 μM) was reduced to CH2, the resulting compound 4 had a dramatically reduced activity, IC50 = 1565 μM.Compound 3a was resolved into (+) and (-) enantiomers and a meso (0) diastereomer using fractional crystallization, diastereomeric tartrate formation, and chiral HPLC.Compared to (-)-3a, the (+) isomer was 15 times more potent when ADP was the agonist and 19 times more active when collagen was used as the agonist.Molecullar modeling of R,R and S,S-3a using the SYBYL program was used to examine their interactions with phosphatidylinositol (PI).There was a better fit between PI and the R,R-3a with the energy of interaction being 17.6 kcal/mol less than that of S,S-3a/PI complex.Although the absolute stereochemistry of individual enantiomers is not known, this study shows that R,R-3a interacts more favorably with PI than does S,S-3a and that (+)-3a is a more potent inhibitor of human platelet aggregation than (-)-3a.It is postulated that because of their lipophilicity, these compounds penetrate the platelet membrane and are then protonated at the pH of the cytosol.The protonated N then neutralizes the anionic charge on the membrane phosphoinositides, thereby rendering them less susceptible to hydrolysis by phospholipase C.Thus, the determinant parameters for optimum antiplatelet activity in 3-carbamoylpiperidines are (1) the amide carbonyl, (2) appropriate stereochemistry of the 3-substituent and (3) a log P value of about 4.5.
- Feng, Zixia,Gollamudi, Ramachander,Dillingham, Elwood O.,Bond, Stephen E.,Lyman, Beverly A.,et, al.
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p. 2952 - 2958
(2007/10/02)
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- Progressive transmetalation of tetranuclear dioxocopper(II) complexes with cobalt reagents
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Aprotic oxidation of tetranuclear copper(I) complexes N4Cu4X4 (I) (N is monodentate N,N-diethylnicotinamide; X is Cl or Br) with dioxygen gives tetranuclear dioxocopper(II) complexes (μ-O)2N4Cu4X4 (II). These targets are transmetalated by excess transmetalators bis(S-methyl isopropylidenehydrazinecarbodithioato)nickel(II) (A) and bis(S-methyl benzylidenehydrazinecarbodithioato)nickel(II) (B) to give isomers of (μ-O)2[NCuNi(H2O)X2]2, Te1 and Te2, respectively. However, if complexes I are first monotransmetalated by A (the metal is Co, Ni, Cu, or Zn) or tris(S-methyl isopropylidenehydrazinecarbodithioato)cobalt(III) (C) and the oxidized, the products are tetramers (μ4-O,μ-O)N3Cu3M(H2O)X 4 (IV). Complexes IV react with excess A (M = Ni) or C to give trimers (μ3-O)N3M3X4 (Tr1) or, when M in IV is Cu (specified as III), with excess A to give the six-member family (μ4-O,μ-O)N3Cu4-x(Ni(H 2O))xCl4 (Te3). It is shown that II (X = Cl) reacts with 1-4 mol of C to give the tetranuclear family (μ-O)2N4Cu4-xCoxCl4 (x = 0-4), which includes the analogue of isomer Te2. Transmetalation of (μ3-O)N3Cu3Cl4 (XIV) with 1-3 mol of C gives the family of Tr1 trimers (μ3-O)N3Cu3-xCoxCl4 (x = 1-3). Structurally different trimers (μ-O)N3(Co,Cu)3Cl4 (Tr2) are obtained by two methods: (1) transmetalation of III with 1-3 mol of C; (2) the four-step sequence (a) transmetalation of I with C and 2 mol of A (M = Cu), (b) oxidation of the product with dioxygen and (c) transmetalation with 1 or 2 mol of C. These two methods give five of the six expected members of the Tr2 family that are distinguishable from Tr1 and from each other by ESR and electronic spectral measurements and by magnetic moment determinations. A trans effect with Co > Cu across μ-oxo bridges influence the course of progressive transmetalations of II and (μ-O)N3(Co,Cu)3Cl4 isomers by C.
- Henary, Maher,Davies, Geoffrey,Abu-Raqabah, Atieh,El-Sayed, Mohamed A.,El-Toukhy, Ahmed
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p. 1872 - 1879
(2008/10/08)
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- Mise au point. Reaction de metallation ortho dirigee des composes aromatiques. Nouvelles methodologies et applications en synthese organique
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In recent years, the aromatic directed metalation reaction has developed into a broadly useful protocol for the regiospecific construction of polysubstituted aromatics and has been applied in efficient total syntheses of diverse classes of natural products.In this review, both methodological and total synthesis advences using primarily the tertiary carboxamide and carbamate as metalation directors are presented.First, general aspects such as the nature of the directed metalation group (DMG) (scheme 1), the effect of two meta-related DMGs on the metalation process (scheme 2), the relative directed metalation abilities of different DMGs (scheme 3), and the scope of reaction with various electrophiles (scheme 4) are first discussed.Next, the advantage of the directed metalation tactic for the synthesis of several classes of natural products (anthramycin, scheme 7 ; angular anthracyclinones, scheme 8 ; and cannabifuran, schemes 10 and 11) are conceptualized and briefly described.Further, the significance of silicon functionality in context of directed metalation chemistry is demonstrated by its use for protection of prefferentially reactive aromatic C-H and C-methyl sites (scheme 12), ipso desilylation (scheme 13), generation of o-quinodimethanes (scheme 14), and overcoming normal Friedel-Crafts regioselectivity in carboannelation (schemes 16-18).Aspects of the tertiary carbamate as a ortho metalation director (scheme 19) are delineated : the development of an anionic ortho-Fries rearrangement (scheme 21) ; a new, also anionic, ortho-tolyl carbamate rearrangement leading to benzofuranones (scheme 22) ; its comparison with tertiary amide a methoxymethoxy as a DMG (scheme 23) ; its use for the generation of benzamide benzyne intermediates (scheme 24) ; metalation of O-pyridyl carbamates (scheme 25) and its synthetic ramifications (schemes 26-28) ; and its application in conjunction with amide metalation for the synthesis of the ochratoxin metaolites (scheme 29).Dimetalation of benzamides (scheme 32), phthalamides (scheme 33), p,p- and o,o-aryl dicarbamates (schemes 34 and 35) are supported by reactions with various electrophiles.To conclude, recent work aimed at connecting the aromatic directed metalation strategy to other modern synthetic methods is described.Coupling the directed metalation process with the radical-induced annelation provides new routes to benzofurans (scheme 36) and furopyridines (scheme 37) and is applied to the preparation of a key synthon for the mould metabolite, aflatoxin (scheme 38).Anionic aromatic and heteroaromatic ring annelation processes which depend upon ortho metalated precursors lead to naphthalene (schemes 39-41) and 4-quinolone (scheme 42) derivatives.Aryl boronic acids with ortho-DMGs, synthesized by metalation-boronation and ipso borodesilylation methods, are cross coupled with aryl bromides under palladium (O) catalysis leading to new routes for the preparation of unsymmetrical biaryls (scheme 45).
- Snieckus, Victor
-
-
- CATALYTIC DOUBLE CARBONYLATION OF ORGANOHALOGEN COMPOUNDS PROMOTED BY PALLADIUM COMPLEXES
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Various organohalogen compounds can be catalytically converted into α-keto amides on reaction with carbon monoxide and amines.Tertiary phosphine-coordinated palladium compounds are particularly suitable as the double carbonylation catalyst.
- Ozawa, Fumiyuki,Soyama, Hidehiko,Yamamoto, Takakazu,Yamamoto, Akio
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p. 3383 - 3386
(2007/10/02)
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- REACTIONS OF THE N,N-DIALKYLPYRIDYLCARBOXYLIC AMIDES WITH LITHIUM AMIDES. REGIOSELECTIVE LITHIATION OF N,N-DIISOPROPYLPYRIDYLCARBOXYLIC AMIDES, A USEFUL METHOD FOR SYNTHESIS OF 2,3- AND 3,4-DISUBSTITUTED PYRIDINES
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The behaviour of the N,N-dimethyl-, N,N-diethyl- and N,N,-diisopropylpyridylcarboxylic amides in the reactions with Et2NLi and iPr2NLi, and a convenient way of synthesis of 2,3- and 3,4-disubstituted pyridines, by the direct lithiation of N,N-diisopropylamides leading subsequently to the ortho new C-C bonds formation, are described.
- Epsztajn, Jan,Berski, Zbigniew,Brzezinski, Jacek Z.,Jozwiak, Andrzej
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p. 4739 - 4742
(2007/10/02)
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- Conformational Studies of N,N-Disubstituted Nicotinamides. NMR Peak Assignments and Utilization of Shift Reagents with 2,6-Dichloronicotinamides
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Europium-induced shift studies are reported for numerous substituted nicotinamides.Without ring substituents, the europium ion interacts with both the pyridine nitrogen and the amide oxygen; however, with 2,6 ring substituents interaction with the amide oxygen is favored.Simple correlations for the induced shifts of the pyridine ring hydrogens are presented and are useful in the conformational analysis of nicotinamides.A combination of variable-temperature nuclear magnetic resonance (VTNMR) studies and europium shift reagents is used to ascertain the preferred conformation in solution of both simple and complex, substituted nicotinamides.
- Newkome, George R.,Kawato, Toshio
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p. 629 - 632
(2007/10/02)
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- Process for making nicotinic acid hydrazides
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A process for condensing a carboxylic acid with ammonia, hydrazine or a substituted hydrazine or a primary or secondary amine to give a compound containing the group --CO--NR'-- where R' is a hydrogen atom, an organic radical, an NH2 group or a substituted NH2 group by the use of a catalyst having a formula M(OR)n X(4-n) wherein M represents titanium or zirconium, R represents an alkyl or aryl radical, X represents a halogen atom and n is an integer from 1 to 4.
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