- α-C-H/N-H Annulation of Alicyclic Amines via Transient Imines: Preparation of Polycyclic Lactams
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Polycyclic lactams are prepared in a single operation from o-toluamides and cyclic amines in a process that involves transient cyclic imines, species that are conveniently obtained in situ from the corresponding lithium amides and simple ketone oxidants. Imines thus generated, such as 1-pyrroline and 1-piperideine, engage lithiated o-toluamides in a facile annulation process. Undesired side reactions such as imine deprotonation and o-toluamide dimerization are suppressed through the judicious choice of reaction conditions.
- Chen, Weijie,Seidel, Daniel
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supporting information
p. 3729 - 3734
(2021/05/31)
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- 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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- Pd-Catalyst Containing a Hemilabile P,C-Hybrid Ligand in Amino Dicarbonylation of Aryl Halides for Synthesis of α-Ketoamides
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The amino dicarbonylation of aryl halides affording α-ketoamides with Pd catalysts is highly dependent on the stereoelectronic properties of the involved ligands. Ionic diphosphine ligand L4 can serve as precursor of a hemilabile P,C (phosphine, carbene)-hybrid ligand to form a stable Pd(II)-complex, Pd-L4. In contrast, analogues L1-L3 with a similar 1-(thiophen-3-yl)-benzimidazolyl skeleton behave as typical (mono/di)phosphines. The catalytic system resulting from the complexation of PdCl2(MeCN)2 and L4 exhibits good catalytic performance in terms of aryl iodides conversion (81-95%) and α-ketoamide selectivity (80-91%), as well as the available recyclability in the RTIL of [Bpy]BF4. The in situ FT-IR analysis reveals that the PdCl2(MeCN)2-L4 catalytic system favors the amino dicarbonylation toward α-ketoamides according to the proposed mechanism of cycle I, which involves two independent CO-insertion steps.
- Yang, Shu-Qing,Yao, Yin-Qing,Chen, Xiao-Chao,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
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p. 1032 - 1041
(2021/05/07)
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- Palladium-Catalyzed N-Acylation of Tertiary Amines by Carboxylic Acids: A Method for the Synthesis of Amides
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A palladium-catalyzed N-acylation of tertiary amines by carboxylic acids was achieved through C-N cleavage. This reaction showed a wide substrate scope. Both aromatic and aliphatic acids served well as the acylating reagents and coupled with tertiary amines to produce the corresponding amides in good to excellent yields. With the strategy, bioactive carboxylic acids were also efficiently modified, highlighting the synthetic value of the process in organic synthesis.
- Li, Zhaohui,Liu, Long,Xu, Kaiqiang,Huang, Tianzeng,Li, Xinyi,Song, Bin,Chen, Tieqiao
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supporting information
p. 5517 - 5521
(2020/07/14)
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- Supramolecular Pd(II) complex of DPPF and dithiolate: An efficient catalyst for amino and phenoxycarbonylation using Co2(CO)8 as sustainable C1 source
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Highly active, efficient and robust “dppf ligated tetranuclear palladium dithiolate complex” was synthesized and applied as a catalyst for chemical fixation of carbon monoxide for the synthesis value added chemicals such as tertiary amide and aromatic esters. The synthesized catalyst was characterized using different analytical techniques such as elemental analysis, 1H and 31P NMR spectroscopy. The use of Co2(CO)8 as a cheap, less toxic and low melting solid surrogate are additional advantages over the current protocol. The catalyst showed superior activity towards the Amino (10?3 mol % catalyst) and Phenoxycarbonylation (10-2 mol % catalyst) and high TON (104 to 103) and TOF (103 to 102 h-1). The Betol and Lintrin (active drug molecules) were synthesized under an optimized reaction condition. The scalability of the current protocol has been demonstrated up-to the gram level.
- Gaikwad, Vinayak V.,Mane, Pravin A.,Dey, Sandip,Patel, Divya,Bhanage, Bhalchandra M.
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- SOLVENTS FOR ORGANOMETALLIC REAGENTS
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In an embodiment, the present disclosure pertains to a solvent including a hydrocarbon oligomer with at least 20 carbon atoms, where the hydrocarbon oligomer has at least one of a low viscosity, a low vapor pressure, and a high flashpoint. In another embodiment, the present disclosure pertains to a solution including a poly(α-olefin) and a reactive organometallic reagent. In a further embodiment, the present disclosure pertains to a solution including an oligomeric hydrocarbon and a reactive organometallic reagent. In an additional embodiment, the present disclosure pertains to a method for creating a solution, where the method includes adding a reactive organometallic reagent to an oligomeric hydrocarbon.
- -
-
Paragraph 0039; 0040
(2020/02/23)
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- Nickel-catalyzed reductive defunctionalization of esters in the absence of an external reductant: Activation of C-O bonds
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The nickel-catalyzed reductive cleavage of esters in the absence of an external reductant, which involves the cleavage of an inert acyl C-O bond in O-Alkyl esters is reported. Various groups, such as N-containing heterocycles, esters, amides, and even arene rings can function as a directing group.
- Iyori, Yasuaki,Takahashi, Kenjiro,Yamazaki, Ken,Ano, Yusuke,Chatani, Naoto
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supporting information
p. 13610 - 13613
(2019/11/14)
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- Asymmetric synthesis of 2,3-dimethoxy-8-oxoberbine, precursor of 0-methylbharatamine
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The enantiospecific and enantioselective syntheses of 2,3-dimethoxy-8-oxoberbine were performed using the lateral retaliation methodology. In the enantiospecific synthesis (4S)-2,2,4-trimethyl-3-(o-toluoyl)-oxazolidine incorporating (S)-alaninol as the ch
- Chrzanowska, Maria,Dreas, Agnieszka,Meissner, Zofia
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p. 1073 - 1085
(2019/08/01)
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- Safer solvents for reactive organometallic reagents
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This paper describes the use of poly(α -olefin)s (PAOs) as safer alternatives to cyclohexane, hexanes, and heptane as solvents for alkyllithium reagents. While PAOs like any alkane are flammable, PAOs do not readily catch on fire because they contain 20 or more carbon atoms, a low volatility, and have a high flash point vis-à-vis alkanes like hexane. Also unlike conventional alkanes, PAOs can be quantitatively separated from polar organic solvents and polar organic products either by a simple gravity separation or by an extraction after a reaction. Any leaching of the PAO solvent into a polar phase during such a separation can be minimized by addition of small amounts of water to the polar phase. However, while these PAO solvents have some physical differences from conventional low molecular weight volatile alkanes, they otherwise behave like alkanes and alkyllithium reagents in these PAO solvents can used in their conventional reactions in these PAO solvents.
- Malinski, Thomas J.,Bergbreiter, David E.
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supporting information
p. 3926 - 3929
(2018/10/02)
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- Restricted amide rotation with steric hindrance induced multiple conformations
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The C–N bond character is dependent directly upon the resonance-contributor structure population driven by the delocalized nitrogen lone-pair of electrons. In the case of N, N-dibenzyl-ortho-toluamide (o-DBET), the molecule adopts subpopulations of confor
- Krishnan,Vazquez, Salvador,Maitra, Kalyani,Maitra, Santanu
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p. 148 - 151
(2017/10/23)
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- Pd/C-catalyzed aminocarbonylation of aryl iodides via oxidative C-N bond activation of tertiary amines to tertiary amides
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This work reports oxidative N-dealkylation/carbonylation of tertiary amines to tertiary amides by using molecular oxygen as a sole oxidant using a Pd/C catalyst. This protocol is free from ligands, additives, bases, and cocatalysts. Different tertiary amines as well as aryl iodides have been examined for this transformation, providing desired products in good to excellent yield.
- Mane, Rajendra S.,Bhanage, Bhalchandra M.
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p. 1223 - 1228
(2016/02/18)
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- Palladium supported on triphenylphosphine-functionalized porous organic polymer: An efficient heterogeneous catalyst for aminocarbonylation
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An efficient route for the catalytic synthesis of aryl amides via the aminocarbonylation of aryl iodides with amines is described using palladium supported on triphenylphosphine-functionalized porous organic polymer (Pd@KAPs(Ph-PPh3)) as the catalyst. Under low carbon monoxide pressure, the catalyst exhibited remarkable activity, and only 0.5 mol% palladium loading was required to achieve moderate to excellent yields (70-97 %) of aryl amides. The catalyst can be easily separated by a simple filtration process and recycled up to seven times with only minor loss of activity. The salient features of this protocol are the simplicity in handling of catalyst, low CO pressure, good functional group tolerance, high catalytic activity, negligible palladium leaching and effective catalyst recyclability.
- Lei, Yizhu,Zhang, Xuefeng,Gu, Yanlong,Hu, Jianglin,Li, Guangxing,Shi, Kaiyi
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- N2 extrusion and co insertion: A novel palladium-catalyzed carbonylative transformation of aryltriazenes
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A novel procedure for the replacement of N2 with CO of aryltriazenes has been developed. Aryltriazenes were converted to the corresponding arylamides catalyzed by 1 mol % of PdCl2/P(o-Tol)3 under CO pressure. In this process, aryldiazonium salts were generated in the presence of 40 mol % of MeSO3H. Nitrogen was released from the substrates and CO formally inserted. Aryl bromides, iodides, alkynes, and free hydroxyl groups can be tolerated in this transformation.
- Li, Wanfang,Wu, Xiao-Feng
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p. 1910 - 1913
(2015/04/27)
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- Palladium-1,10-phenanthroline complex encaged in y zeolite: An efficient and highly recyclable heterogeneous catalyst for aminocarbonylation
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A promising route for catalytic synthesis of amides by aminocarbonylation of aryl iodides with amines is described using a palladium-1,10-phenanthroline complex encaged in Y zeolite. Complete conversions for aryl iodides and good to excellent yields (71-97%) of various amides were obtained at low Pd loadings of 0.6 mol%. The turnover frequency (TOF) could be up to 139 h-1. A satisfactory yield was obtained even after the catalyst was reused 16 times and the total turnover number (TON) for the 16 cycles was up to 2250. As evidenced by atomic absorption spectrophotometry, UV-vis spectroscopy and X-ray photoelectron spectroscopy, the palladium complex could well nestle down in the supercages of the zeolite without leaching during the recycling process. The significantly enhanced recyclability could be attributed to the double-protection strategy provided by the ligand and the zeolite structure for Pd0 species generated in situ within supercages preventing the migration and leaching of palladium. The supported catalyst has the advantages of easy handing, good to excellent yields, and outstanding recycling capacity for aminocarbonylation reactions of aryl iodides.
- Mei, Hui,Hu, Jianglin,Xiao, Se,Lei, Yizhu,Li, Guangxing
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- NHC-Pd complex-catalyzed double carbonylation of aryl iodides with secondary amines to α-keto amides
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A series of palladium-NHC compounds were prepared and their catalytic activity in the double carbonylation of aryl iodides to synthesize α-keto amides were examined. Palladium complexes bearing mixed NHC-phosphine exhibited high efficiency for the double carbonylation reaction. The effects of different solvents, base, temperature, carbon monoxide (CO), pressure, various amine and aryl iodides were investigated. Both electron-rich and electron-deficient aryl iodides afforded the corresponding substituted α-keto amides in moderate to good yields. A possible mechanism was also proposed. Copyright
- Zheng, Shuzhan,Wang, Yan,Zhang, Chunyan,Liu, Jianhua,Xia, Chungu
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- An easy access to tertiary amides from aldehydes and N,N- dialkylchlorothiophosphoramidates
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A mechanistically unprecedented approach for the formation of tertiary amides from N,N-dialkylchlorothiophosphoramidates and aldehydes has been developed. The reaction occurred via the activation of aldehydes with N,N-dialkylchlorothiophosphoramidates followed by amidation with dialkylamine pendent of the same phosphoramidate.
- Pathak, Uma,Bhattacharyya, Shubhankar,Pandey, Lokesh Kumar,Mathur, Sweta,Jain, Rajeev
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p. 3900 - 3903
(2014/01/06)
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- Branch-selective, Iridium-catalyzed hydroarylation of monosubstituted alkenes via a cooperative destabilization strategy
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Highly branch-selective, carbonyl-directed hydroarylations of monosubstituted alkenes are described. The chemistry relies upon a cationic Ir(I) catalyst modified with an electron deficient, wide bite angle bisphosphine ligand. This work provides a regioisomeric alternative to the Murai hydroarylation protocol.
- Crisenza, Giacomo E. M.,McCreanor, Niall G.,Bower, John F.
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supporting information
p. 10258 - 10261
(2014/08/05)
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- Synthesis of 12-oxobenzo[c]phenanthridinones and 4-substituted 3-arylisoquinolones via Vilsmeier-Haack reaction
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Vilsmeier-Haack reaction on 3-arylisoquinolones resulted in versatile 4-formylated 3-arylisoquinolones that were further derivatized into 12-oxobenzo[c]phenanthridinones, 4-alkoxymethyl-3-arylisoquinolones, 3-aryl-4-phenoxymethylisoquinolones, 4-aminometh
- Khadka, Daulat Bikram,Yang, Su Hui,Cho, Suk Hee,Zhao, Chao,Cho, Won-Jea
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p. 250 - 261
(2012/01/05)
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- Synthesis of 7-(4-piperidyl)- [1,6]naphthyridin-5-one and 3-(4-piperidyl)isoqunolin-1-one
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7-(4-Piperidyl)[1,6]napththiridin-5-one was synthesized on the basis of 2-methylnicotinic acid. 3-(4-Piperidyl)isoquinolin-1-one was synthesized from the diethylamide of o-toluic acid and Weinreb′s amide of N-Boc-isonipecotic acid.
- Kovalskiy,Perevalov
-
experimental part
p. 1503 - 1507
(2010/07/04)
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- Total synthesis of 8-oxypseudopalmatine and 8-oxypseudoberberine via ring-closing metathesis
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Concise synthesis of 8-oxypseudopalmatine and 8-oxypseudoberberine has been achieved using ruthenium-catalyzed ring-closing metathesis (RCM) as the key step, in which the RCM substrates, 3-arylisoquinolinones, were prepared by lithiated cycloaddition reac
- Van, Hue Thi My,Yang, Su Hui,Khadka, Daulat Bikram,Kim, Yong-Chul,Cho, Won-Jea
-
experimental part
p. 10142 - 10148
(2010/02/27)
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- Application of directed orthometalation toward the synthesis of aryl siloxanes
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A selection of ortho-substituted aryl siloxanes have been prepared by directed orthometalation protocols. These siloxanes can be prepared in high yields and purity by use of a diverse selection of ortho-directing groups and electrophilic siloxane derivatives. The siloxanes are employed in palladium-catalyzed cross-coupling reactions with aryl bromides to generate unsymmetrical orthosubstituted biaryls in good to excellent yields.
- Seganish, W. Michael,DeShong, Philip
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p. 6790 - 6795
(2007/10/03)
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- Asymmetric synthesis of 3-substituted dihydro-2H-isoquinolin-1-ones, dihydro- and tetrahydroisoquinolines via 1,2-addition/ring closure
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The asymmetric synthesis of 3-substituted dihydro-2H-isoquinolin-1-ones, dihydro- and tetrahydroisoquinolines is described. The key operation is a tandem 1,2-addition/ring closure sequence employing lithiated ortho-toluamides and aldehyde SAMP- or RAMP-hydrazones as substrates, followed by N-N bond cleavage to remove the auxiliary. Moderate to good yields and high enantiomeric excesses (ee = 85-99%) are reached.
- Enders, Dieter,Braig, Volker,Boudou, Marine,Raabe, Gerhard
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p. 2980 - 2990
(2007/10/03)
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- The extraordinary reactions of phenyldimethylsilyllithium with N,N-disubstituted amides
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The reactions of the silyllithium reagent with tertiary amides was discussed. The enediamines were easily isomerized from cis to trans, easily oxidized to dienediamines and were hydrolyzed to α-aminoketones. If the two equivalents of the silyllithium reagent were used, the product was an α-silylamine. The results show that each member of the homologous series of amides gives rise to a substantially different product.
- Buswell, Marina,Fleming, Ian,Ghosh, Usha,Mack, Stephen,Russell, Matthew,Clark, Barry P.
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p. 3006 - 3017
(2007/10/03)
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- A direct and mild conversion of tertiary aryl amides to methyl esters using trimethyloxonium tetrafluoroborate: A very useful complement to directed metalation reactions
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The scope and generality of a direct process for the conversion of tertiary amides directly to methyl esters has been investigated. The process involves a two-step, one pot procedure in which a tertiary amide is first treated with trimethyloxonium tetrafluoroborate to generate an imidate intermediate which is then hydrolyzed, generally by the addition of saturated aqueous sodium bicarbonate solution. Although this process fails for aliphatic amides, very good yields are realized for a variety of amides derived from aromatic carboxylic acids. Steric hindrance at the N-alkyl group is well tolerated; thus N,N-dimethyl, -diethyl, and -diisopropyl amides can all be utilized successfully. (C) 2000 Elsevier Science Ltd.
- Keck, Gary E,McLaws, Mark D,Wager, Travis T
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p. 9875 - 9883
(2007/10/03)
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- Transmetalation and Reverse Transmetalation on Ortho-Activated Aromatic Compounds: A Direct Route to o,o'-Disubstituted Benzenes
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Mercury Substitution ortho to appropriately activated benzenes was achieved by using the reagent lithium tetramethylpiperidide (LiTMP)/ mercuric chloride.LiTMP provides for lithiation ortho to the activating group; HgCl2 functions as an in situ trap effecting mercury-for-lithium transmetalation.Ortho, ortho'-dimercuration was also observed; this occurs by iteration of the transmetalation process.The effects of major variables on these reactions were studied by using primarily N,N-diethylbenzamide as the activated substrate.Isopropyl benzoate, 2-phenyl-4,4-dimethyloxazoline, etc. were found to behave similarly.The mercurated aromatics could be converted to the corresponding haloaromatics in excellent yield, providing, for example, a good synthesis of o,o'-diiodo-N,N-diethylbenzamide, otherwise difficultly accessible.Reverse transmetalation methodology was employed to prepare o,o'-dilithiated-N,N-diethylbenzamide, which was characterized by its reactions with electrophiles.
- Eaton, Philip E.,Martin, Ronald M.
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p. 2728 - 2732
(2007/10/02)
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- Palladium-Catalysed Double Carbonylation of Aryl Halides To Give α-Keto Amides. Mechanistic Studies
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Various aryl halides are catalytically converted into α-keto amides and amides on treatment with secondary amines and carbon monoxide.Palladium complexes containing tertiary phosphine ligands, particularly diphenylmethylphosphine and 1,4-bis(diphenylphosphino)butane, are most effective among other transition-metal complexes.Detailed examination of factors controlling the reaction rates and selectivity for α-keto amide formation revealed the following characteristics of the reactions. (a) Reactivity of phenyl halide decreases in the order PhI > PhBr >> PhCl. (b) Oxidative addition of phenyl bromide constitutes the rate-determining step in double carbonylation of phenyl bromide, whereas in the reaction of phenyl iodide the rate determinig step is associated with the reaction of a catalitically active palladium species with carbon monoxide. (c) Introduction of an electron-withdrawing substituent into the para position of phenyl halide enhances the reactivity but decreases the selectivity for α-keto amide. (d) Employment of amines of high basicity (pKb Et2NH > piperidine > hexamethyleneimine > Me2NH > pyrrolidine probably reflects the decrease in steric bulkiness of amines. (f) Although primary amines are in general not suitable for the double carbonylation, tert-butylamine can be used because of its inertness to the product α-keto amide.Reactivity of trans-PdPh(I)(PMePh2)2 and trans-Pd(COPh)I(PMePh2)2, supposed intermediates in the catalytic reaction of PhI, toward amines and CO was examined.The relative reactivity of six secondary amines with the benzoylpalladium complex increasing in the order Pr2NH Et2NH piperidine Me2NH hexamethyleneimine pyrrolidine was found to be inversely correlated with decreasing selectivity order for α-keto amide formation in the catalytic systems.On the basis of the experimental results, a mechanism consisting of two catalytic cycles to produce α-keto amides and amides has been proposed.
- Ozawa, Fumiyuki,Soyama, Hidehiko,Yanagihara, Hisayoshi,Aoyama, Issei,Takino, Hiroaki,et al.
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p. 3235 - 3245
(2007/10/02)
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- DILITHIATED SYNTHONS OF TERTIARY BENZAMIDES, PHTHALAMIDES, AND O,O'-ARYL DICARBAMATES
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Dilithiated species 1, 2, and 3, generated by metal-halogen exchange and directed ortho metalation, undergo reaction with electrophiles to afford, in high yield, polysubstituted aromatics 6, 7, and 8 respectively; 9 is formed via a bis anionic Fries rearr
- Mills, R. J.,Horvath, R. F.,Sibi, M. P.,Snieckus V.
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p. 1145 - 1148
(2007/10/02)
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- INVESTIGATIONS ON N,N-DIALKYLBENZAMIDES BY NMR SPECTROSCOPY. PART IV. COMPARISON OF BARRIERS TO ROTATION ABOUT THE AMINE C-N BOND IN ORTHO-SUBSTITUTED N,N-DIMETHYL-AND N,N-DIETHYLBENZAMIDES
-
The barriers to rotation about the amide C-N bond in a series of ortho-substituted N,N-dimethyl and N,N-diethylbenzamides have been compared.It has been stated that for most of substituents, namely CH3, Cl, Br, I and NO2, the rates of rotation in both series of compounds are identical within the accuracy of measurement (kEt/kMe ca.1).The remaining compounds (F, CN, CH3) show a higher rate of rotation in the series of diethylbenzamides (kEt/kMe ca.1,5).An exception are the OH derivatives in which the internal H-bond is present and because of that the barrier to rotation is lowered and the kEt/kMe ratio raised up to 2.3.
- Gryf-Keller, Adam,Terpinski, Jacek,Zajaczkowska-Terpinska, Ewa
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p. 429 - 434
(2007/10/02)
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- The Tertiary Amide as an Effective Director of Ortho Lithiation
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The tertiary amides N,N-diethylbenzamide (1) and N,N-diisopropylbenzamide (3) give the ortho-lithiated species 2 on treatment with sec-BuLi/TMEDA or n-BuLi/TMEDA, respectively, at -78 deg.Lithiation of 1 followed by rection with either methyl iodide, ethyl iodide, benzophenone, acetone, benzaldehyde, or trimethoxyborane-hydrogen peroxide gives the expected ortho substituted product.Intramolecular competition between the diethyloamido and chloro, methoxyl, sulfonamido, (dimethylamino)methyl, or oxazolino functions in ortho- and para-substituted benzamides establishes the tertiary amido group to be more effective in directing metalation than any noncarboxamide functional group under the prescribed conditions.Complimentarity of directing effects is observed with the chloro and methoxyl groups in the meta-substituted diethylbenzamides but not with the methyl group.The secondary amide is found to have a directing ability comparable to the tertiary amide with sec-BuLi/TMEDA at -78 deg in THF although the yields are low. 13C NMR chemical shifts are particularly useful for the structural assignments which are confirmed chemically by lactonization of some products.A labeling study with N,N-diisopropyl-2,6-dideuteriobenzamide suggests that lithiation of the ortho position of 3 is direct and not the result of rearrangement of an initially formed α-aza anion.Control of metalation at the ortho or benzylic position by proper selection of the organolithium base is illustrated for N,N-diisopropyl-p-toluamide.The value of the tertiary amide for control of ortho lithiations and regiospecific aromatic substitutions is noted.
- Beak, Peter,Brown, Roger A.
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-