- An Efficient Palladium-Catalysed Aminocarbonylation of Benzyl Chlorides
-
An improved procedure for the aminocarbonylation of benzyl chloride derivatives using carbon monoxide and either primary or secondary amines has been developed. Studying the competing background alkylation reaction allowed the solvent and base to be selected for a simple catalyst screen, which, in turn, enabled the discovery of a method for the preparation of 2-arylacetamides under mild conditions, with minimal side-products using an inexpensive phosphine ligand. This non-traditional optimisation strategy allowed us to overcome the background alkylation, which has been cited as justification for the development of more complex and less atom-economical approaches.
- Oram, Niall,Richardson, Jeffery,Rilvin-Derrick, Eloise
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p. 369 - 372
(2020/02/27)
-
- Synthesis of Novel Heterocycles by Amide Activation and Umpolung Cyclization
-
Herein, we report a metal-free synthesis of cyclic amidines, oxazines, and an oxazinone under mild conditions by electrophilic amide activation. This strategy features an unusual Umpolung cyclization mode and enables the smooth union of α-aryl amides and diverse alkylazides, effectively rerouting our previously reported α-amination transform.
- Maulide, Nuno,Riomet, Margaux,Roller, Alexander,Zhang, Haoqi
-
supporting information
(2020/03/24)
-
- Palladium-catalyzed carbonylation of benzylic ammonium salts to amides and esters: Via C-N bond activation
-
An efficient palladium-catalyzed carbonylation reaction of readily available quaternary ammonium salts with CO is reported for the first time to afford arylacetamides and arylacetic acid esters via benzylic C-N bond cleavage. This protocol features mild reaction conditions under atmospheric pressure of CO, a redox-neutral process without an additional oxidant, and a broad substrate scope for various kinds of amines, alcohols and phenols.
- Yu, Weijie,Yang, Shuwu,Xiong, Fei,Fan, Tianxiang,Feng, Yan,Huang, Yuanyuan,Fu, Junkai,Wang, Tao
-
supporting information
p. 3099 - 3103
(2018/05/22)
-
- Phototriggered Dehydration Condensation Using an Aminocyclopropenone
-
A phototriggered dehydration condensation using an aminocyclopropenone has been developed. The UV irradiation of an aminocyclopropenone generated a highly reactive ynamine in situ and the dehydration condensation of a carboxylic acid and an amine coexisting in the reaction solution smoothly proceeded to afford an amide. This reaction is completely controllable by the ON/OFF states of a UV lamp.
- Mishiro, Kenji,Yushima, Yuki,Kunishima, Munetaka
-
supporting information
p. 4912 - 4915
(2017/09/23)
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- Charge-Transfer Complex Promoted C-N Bond Activation for Ni-Catalyzed Carbonylation
-
A new strategy was developed for activation of C-N bond via formation of an amine-I2 charge-transfer complex, which facilitates the inert C-N bond activation via oxidative addition with Ni(0). This strategy has been successfully applied in the Ni-catalyzed carbonylation of benzylamines via direct insertion of CO into the C-N bond, which provided a straightforward and rapid approach to arylacetamides in the presence of catalytic amounts of I2 and Ni catalyst. Mechanistic studies suggested that a benzyl radical generated via the oxidative addition was involved in the present reaction.
- Yu, Hui,Gao, Bao,Hu, Bin,Huang, Hanmin
-
supporting information
p. 3520 - 3523
(2017/07/17)
-
- Sunlight assisted direct amide formation: Via a charge-transfer complex
-
We report on the use of charge-transfer complexes between amines and carbon tetrachloride, as a novel way to activate the amine for photochemical reactions. This principle is demonstrated in a mild, transition metal free, visible light assisted, dealkylative amide formation from feedstock carboxylic acids and amines. The low absorption coefficient of the complex allows deep light penetration and thus scale up to a gram scale.
- Cohen, Irit,Mishra, Abhaya K.,Parvari, Galit,Edrei, Rachel,Dantus, Mauricio,Eichen, Yoav,Szpilman, Alex M.
-
supporting information
p. 10128 - 10131
(2017/09/23)
-
- Mechanistic Pathways in Amide Activation: Flexible Synthesis of Oxazoles and Imidazoles
-
The preparation of substituted aminooxazoles and aminoimidazoles from α-arylamides and α-aminoamides through triflic anhydride-mediated amide activation is reported. These reactions proceed via the intermediacy of nitrilium adducts and feature N-oxide-promoted umpolung of the α-position of amides as well as a mechanistically intriguing sequence that results in sulfonyl migration from nitrogen to carbon. Quantum-chemical mechanistic analysis sheds light on the intricacies of the process.
- Di Mauro, Giovanni,Maryasin, Boris,Kaiser, Daniel,Shaaban, Saad,González, Leticia,Maulide, Nuno
-
supporting information
p. 3815 - 3818
(2017/07/26)
-
- Metal-Free Amidation of Acids with Formamides and T3P
-
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
-
p. 2069 - 2078
(2016/07/06)
-
- Synthesis of Unsymmetrical Diaryl Acetamides, Benzofurans, Benzophenones, and Xanthenes by Transition-Metal-Free Oxidative Cross-Coupling of sp3 and sp2 C-H Bonds
-
A chemo- and regioselective intermolecular sp3 C-H and sp2 C-H coupling reaction for C-C bond formation is described to access unsymmetrical diaryl acetamides under TM-free conditions from sec- and tert-arylacetamides and nitroarenes using tert-butoxide base in DMSO at room temperature. The coupling partners with sensitive functionalities such as chloro, bromo, hydroxy, and cyano were also amenable to the developed reaction. Synthesized α-(2/4-nitroaryl) phenylacetamides have been transformed into biologically important benzofurans, xanthenes, diaryl indoles, and unsymmetrical benzophenones by novel routes without applying a transition metal. Overall, an economical, yet efficient, strategy has been devised to access unsymmetrical diarylacetamides with the possibility of their further elaboration into a variety of biologically important heterocycles. Mechanistic understanding suggests that the reaction proceeds by a nucleophilic addition of a phenylacetamide carbanion, which is generated in the presence of tert-butoxide base, to the para or ortho (if para is substituted) position of nitrobenzene. The formed α-(4-nitrocyclohexa-2,4-dien-1-yl) phenylacetamide anion intermediate oxidized by a basic solution of DMSO or atmospheric oxygen led to the desired sp3 C-H and sp2 C-H coupled α-(2/4-nitroaryl) phenylacetamides.
- Rathore, Vandana,Sattar, Moh.,Kumar, Raushan,Kumar, Sangit
-
p. 9206 - 9218
(2016/10/14)
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- Sterically Demanding Oxidative Amidation of α-Substituted Malononitriles with Amines Using O2
-
An efficient amidation method between readily available 1,1-dicyanoalkanes and either chiral or nonchiral amines was realized simply with molecular oxygen and a carbonate base. This oxidative protocol can be applied to both sterically and electronically challenging substrates in a highly chemoselective, practical, and rapid manner. The use of cyclopropyl and thioether substrates support the radical formation of α-peroxy malononitrile species, which can cyclize to dioxiranes that can monooxygenate malononitrile α-carbanions to afford activated acyl cyanides capable of reacting with amine nucleophiles.
- Li, Jing,Lear, Martin J.,Hayashi, Yujiro
-
supporting information
p. 9060 - 9064
(2016/07/26)
-
- A one-pot amidation of primary nitroalkanes
-
It has been over a half-century since Kornblum demonstrated the conversion of a primary nitroalkane to a carboxylic acid; addition of an amine results in carboxylic acid formation as well. We describe the formation of amides from terminal nitroalkanes in a two-step, one-pot reaction involving tandem halogenation/umpolung amide synthesis (UmAS).
- Schwieter, Kenneth E.,Johnston, Jeffrey N.
-
supporting information
p. 152 - 155
(2015/12/26)
-
- Cu-catalyzed aerobic oxidative three-component coupling route to N -sulfonyl amidines via an ynamine intermediate
-
Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables efficient synthesis of amidines. The use of Cu(OTf)2 (5 mol %) produces amidines selectively without Glaser-Hay alkyne homocoupling products. Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amine, followed by hydroamidation of the ynamine intermediate with the sulfonamide.
- Kim, Jinho,Stahl, Shannon S.
-
p. 2448 - 2454
(2015/04/14)
-
- PROCESS FOR PREPARATION OF N,N-DI SUBSTITUTED CARBOXAMIDES
-
The present disclosure relates to a single pot process for preparation of a N,N-di substituted carboxamide compounds of formula (I), said process comprising: reacting a carboxylic acid with a di-substituted carbamoyl chloride in presence of an organic tertiary base to obtain the N,N-di substituted carboxamide compounds of formula (I). The process of the present disclosure involves a simple step, and it is energy and time saving process for preparation of N,N-di substituted carboxamides.
- -
-
Paragraph 0093-0094
(2015/05/13)
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- A general and practical palladium-catalyzed direct a-arylation of amides with aryl halides
-
An efficient system for the direct catalytic intermolecular α-arylation of acetamide derivatives with aryl bromides and chlorides is presented. The palladium catalyst is supported by Kwong's indolebased phosphine ligand and provides monoarylated amides in up to 95% yield. Excellent chemoselectivities (>10:1) in the mono- and diarylation with aryl bromides were achieved by careful selection of bases, solvents, and stoichiometry. Under the coupling conditions, the weakly acidic α-protons of amides (pK a up to 35) were reversibly depotonated by lithium tert-butoxide (LiO-t-Bu), sodium tert-butoxide (NaO-t-Bu) or sodium bis(trimethylsilyl)amide [NaN(SiMe3)2].
- Zheng, Bing,Jia, Tiezheng,Walsh, Patrick J.
-
supporting information
p. 165 - 178
(2014/03/21)
-
- Silver acetate-assisted formation of amides from acyl chlorides
-
A mild method for the aminolysis of carboxylic acid chlorides to give amides is disclosed. Reactions are carried out in the presence of silver acetate in non-aqueous environments under heterogeneous phase conditions. Amides are easily recovered in very good to excellent yields and without racemization. The approach is successful in forming peptide bonds starting from N-(4-nitrobenzenesulfonyl)-amino acid chlorides and allows the formation of dipeptides also when N-methylated amino acid derivatives are used.
- Leggio,Belsito,Di Gioia,Leotta,Romio,Siciliano,Liguori
-
p. 199 - 202
(2015/02/02)
-
- Base-promoted synthesis of coumarins from salicylaldehydes and aryl-substituted 1,1-dibromo-1-alkenes under transition-metal-free conditions
-
Facile synthesis of coumarin via the tandem reaction of salicylaldehyde with aryl-substituted 1,1-dibromo-1-alkene was developed. This new protocol proceeds smoothly under mild and transition-metal-free conditions, it allows rapid access to coumarins containing various heteroatoms that are more difficult to prepare by traditional methods. Based on the isolated intermediate of 4-(diethylamino)-3-phenylchroman-2-one and detailed mechanistic studies, a credible tandem pathway was proposed.
- Liu, Jianming,Zhang, Xin,Shi, Lijun,Liu, Muwen,Yue, Yuanyuan,Li, Fuwei,Zhuo, Kelei
-
supporting information
p. 9887 - 9890
(2014/08/18)
-
- Direct amidation of carboxylic acids with tertiary amines: Amide formation over copper catalysts through C-N bond cleavage
-
A copper-catalyzed system for the amidation of carboxylic acids with tert-amines through C-N bond cleavage was developed. This protocol is practical and represents a simple way to produce functionalized amides from basic starting materials in moderate to good yields. A plausible mechanism is proposed for the reaction. Copyright
- Xiong, Biquan,Zhu, Longzhi,Feng, Xiaofeng,Lei, Jian,Chen, Tieqiao,Zhou, Yongbo,Han, Li-Biao,Au, Chak-Tong,Yin, Shuang-Feng
-
supporting information
p. 4244 - 4247
(2014/07/21)
-
- Ketene reactions with tertiary amines
-
Tertiary amines react rapidly and reversibly with arylketenes in acetonitrile forming observable zwitterions, and these undergo amine catalyzed dealkylation forming N,N-disubstituted amides. Reactions of N- methyldialkylamines show a strong preference for methyl group loss by displacement, as predicted by computational studies. Loss of ethyl groups in reactions with triethylamine also occur by displacement, but preferential loss of isopropyl groups in the phenylketene reaction with diisopropylethylamine evidently involves elimination. Quinuclidine rapidly forms long-lived zwitterions with arylketenes, providing a model for catalysis by cinchona and related alkaloids in stereoselective additions to ketenes.
- Allen, Annette D.,Andraos, John,Tidwell, Thomas T.,Vukovic, Sinisa
-
p. 679 - 685
(2014/04/03)
-
- Umpolung Amide Synthesis using substoichiometric N-iodosuccinimide (NIS) and oxygen AS a terminal oxidant
-
Umpolung Amide Synthesis (UmAS) provides direct access to amides from an α-bromo nitroalkane and an amine. Based on its mechanistic bifurcation after convergent C-N bond formation, depending on the absence or presence of oxygen, UmAS using substoichiometric N-iodosuccinimide (NIS) under aerobic conditions has been developed. In combination with the enantioselective preparation of α-bromo nitroalkane donors, this protocol realizes the goal of enantioselective α-amino amide and peptide synthesis based solely on catalytic methods.
- Schwieter, Kenneth E.,Shen, Bo,Shackleford, Jessica P.,Leighty, Matthew W.,Johnston, Jeffrey N.
-
supporting information
p. 4714 - 4717
(2015/04/27)
-
- Alcohol assisted C-C bond breaking: Copper-catalyzed deacetylative α-arylation of β-keto esters and amides
-
A method of alcohol-assisted copper-catalyzed highly selective deacetylative α-arylation of β-keto esters and amides has been demonstrated, which illustrated an efficient example of achieving α-aryl esters and amides. From the synthetic point of view, this arylation protocol is general and practical, representing a simple way to produce α-arylated carbonyl compounds from basic starting materials at low cost.
- Ke, Jie,He, Chuan,Liu, Huiying,Xu, Huan,Lei, Aiwen
-
supporting information
p. 6767 - 6769
(2013/07/26)
-
- Pd(ii)-catalyzed decarboxylative acylation of phenylacetamides with α-oxocarboxylic acids via C-H bond activation
-
A palladium-catalyzed decarboxylative acylation of phenylacetamides with α-oxocarboxylic acids via C-H bond activation is described. This protocol provides efficient access to a range of ortho-acyl phenylacetamides, which can be easily converted to 3-isochromanone derivatives. The Royal Society of Chemistry 2013.
- Park, Jihye,Kim, Minyoung,Sharma, Satyasheel,Park, Eonjeong,Kim, Aejin,Lee, Sang Hwi,Kwak, Jong Hwan,Jung, Young Hoon,Kim, In Su
-
supporting information
p. 1654 - 1656
(2013/03/14)
-
- Amination of phenylketenes. Substituent effect on amine-catalyzed tautomerization of amide enol
-
The transient intermediates with infrared bands at 1676-1680 cm -1 observed for reaction of substituted phenylketenes with diethylamine in acetonitrile were suggested to be the amide enols rather than the zwitterions on the basis of the theoretical calculations. A single broad band at 1674 cm-1 observed for reaction with the primary amines was attributed to overlap of two bands of the intermediate (amide enol) and the final product (amide). The substituent effect for the second-order rate constants of diethylamine-catalyzed tautomerization of the amide enol intermediates to give the amides was analyzed successfully by the Yukawa-Tsuno equation, giving a ρ value of 0.63 and an r- value of 1.31. The r- value larger than unity for pKa of phenols indicates that the negative charge formed at an oxygen atom of the amide enol at the transition state is significantly delocalized into the aromatic π-system through the ethenyl group. This r- value was considered to reflect an intrinsic property of β-phenylenolate skeleton. A remarkably small ρ value attributes to the cyclic transition structure where the negative charge disperses in a six-member ring. Copyright 2013 John Wiley & Sons, Ltd. The substituent effect for the reaction of the amide enol intermediate generated from phenylketene with diethylamine has been analyzed. The large r- of 1.31 was attributed to an intrinsic property of β-phenylenolate skeleton. A remarkably small ρ of 0.63 suggested the cyclic transition structure. Copyright
- Badal, Md. Mizanur Rahman,Zhang, Min,Kobayashi, Shinjiro,Mishima, Masaaki
-
supporting information
p. 1071 - 1076
(2014/01/06)
-
- Palladium-catalyzed direct intermolecular α-arylation of amides with aryl chlorides
-
An efficient catalytic system for the direct intermolecular α-arylation of acetamide derivatives with aryl chlorides is presented. Chemoselectivities up to 10:1 in the mono-and diarylation of acetamides were achieved by careful selection of bases, solvent
- Zheng, Bing,Jia, Tiezheng,Walsh, Patrick J.
-
supporting information
p. 4190 - 4193
(2013/09/12)
-
- Palladium-catalyzed oxidative aminocarbonylation: A new entry to amides via C-H activation
-
A novel palladium-catalyzed oxidative aminocarbonylation reaction via C(sp3)-H activation was established, which provides a convenient and general method for the construction of arylacetamides via the carbonylation reaction of alkyl aromatics and amines. By using this protocol, the marketed drug ibuprofen could be easily obtained.
- Xie, Pan,Xia, Chungu,Huang, Hanmin
-
supporting information
p. 3370 - 3373
(2013/07/26)
-
- PROCESS FOR PREPARATION OF N,N-DI SUBSTITUTED CARBOXAMIDES
-
The present disclosure relates to a single pot process for preparation of a N,N-di substituted carboxamide compounds of formula (I), said process comprising: reacting a carboxylic acid with a di-substituted carbamoyl chloride in presence of an organic tertiary base to obtain the N,N-di substituted carboxamide compounds of formula (I). The process of the present disclosure involves a simple step, and it is energy and time saving process for preparation of N, N-di substituted carboxamides.
- -
-
Page/Page column 12
(2013/05/22)
-
- Ring splitting of azetidin-2-ones via radical anions
-
The radical anions of azetidin-2-ones, generated by UV-irradiation in the presence of triethylamine, undergo ring-splitting via N-C4 or C3-C4 bond breaking, leading to open-chain amides. This reactivity diverges from that found for the neutral excited states, which is characterised by α-cleavage. The preference for β-cleavage is supported by DFT theoretical calculations on the energy barriers associated with the involved transition states. Thus, injection of one electron into the azetidin-2-one moiety constitutes a complementary activation strategy which may be exploited to produce new chemistry.
- Perez-Ruiz, Raul,Saez, Jose A.,Domingo, Luis R.,Jimenez, M. Consuelo,Miranda, Miguel A.
-
p. 7928 - 7932
(2013/06/27)
-
- Reductive hydroxyalkylation/alkylation of amines with lactones/esters
-
We have developed a one-pot method for the direct intermolecular reductive hydroxyalkylation or alkylation of amines using lactones or esters as the hydroxyalkylating/alkylating reagents. The method is based on the in situ amidation of lactones/esters with DIBAL-H-amine complex (for primary amines) or DIBAL-H-amine hydrochloride salt complex (for secondary amines), followed by reduction of the amides with an excess of DIBAL-H. Different from the reduction of Weinreb amides with DIBAL-H where aldehydes are formed, the reduction of the in situ formed Weinreb amides yielded amines. Moreover, this method is not limited to Weinreb amides, instead, it also works for other amides in general. A plausible mechanism is suggested to account for the outcome of the reactions.
- Wang, Yu-Huang,Ye, Jian-Liang,Wang, Ai-E,Huang, Pei-Qiang
-
experimental part
p. 6504 - 6511
(2012/09/08)
-
- Preparation of tertiary amides via aryl, heteroaryl, and benzyl organozinc reagents; Scope and limitations
-
A facile synthetic protocol for the preparation of tertiary amides has been developed. The title compounds have been successfully obtained by the Pd-catalyzed cross-coupling reactions of readily available aryl and benzyl organozinc reagents with the appropriate carbamoyl chlorides.
- Rieke, Reuben D.,Kim, Seung-Hoi
-
experimental part
p. 3478 - 3481
(2012/08/13)
-
- Practical synthesis of amides from alkynyl bromides, amines, and water
-
A general and efficient method for the synthesis of a wide range of amides is described here. The reactions were conducted under convenient conditions and provided secondary and tertiary amides in moderate to excellent yields. A variety of amines and substituted alkynyl bromides were used to investigate the scope of the reactions.
- Chen, Zheng-Wang,Jiang, Huan-Feng,Pan, Xiao-Yan,He, Zai-Jun
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experimental part
p. 5920 - 5927
(2011/09/19)
-
- Umpolung reactivity in amide and peptide synthesis
-
The amide bond is one of natureg€s most common functional and structural elements, as the backbones of all natural peptides and proteins are composed of amide bonds. Amides are also present in many therapeutic small molecules. The construction of amide bonds using available methods relies principally on dehydrative approaches, although oxidative and radical-based methods are representative alternatives. In nearly every example, carbon and nitrogen bear electrophilic and nucleophilic character, respectively, during the carbong€"nitrogen bond-forming step. Here we show that activation of amines and nitroalkanes with an electrophilic iodine source can lead directly to amide products. Preliminary observations support a mechanism in which the polarities of the two reactants are reversed (German, umpolung) during carbong€"nitrogen bond formation relative to traditional approaches. The use of nitroalkanes as acyl anion equivalents provides a conceptually innovative approach to amide and peptide synthesis, and one that might ultimately provide for efficient peptide synthesis that is fully reliant on enantioselective methods.
- Shen, Bo,Makley, Dawn M.,Johnston, Jeffrey N.
-
experimental part
p. 1027 - 1032
(2011/08/06)
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- One-pot amide synthesis from allyl or benzyl halides and amines by Pd-catalysed carbonylation
-
Amides can be prepared from allyl or benzyl halides and primary or secondary amines, using Pd(0) catalyst under CO pressure, in a one-pot synthesis. The reaction proceeds through the acyl palladium halide formation which undergoes an acylic nucleophilic substitution from the amine.
- Troisi, Luigino,Granito, Catia,Rosato, Francesca,Videtta, Valeria
-
experimental part
p. 371 - 373
(2010/03/24)
-
- Highly efficient synthesis of aldenamines from carboxamides by iridium-catalyzed silane-reduction/dehydration under mild conditions
-
The combination of IrCl(CO)(PPh3)2 with 1,1,3,3-tetramethyldisiloxane or poly(methylhydrosiloxane) (PMHS) is found to be an efficient catalyst system for the preparation of aldenamines from carboxamides; in particular, facile removal of silicone and iridium residues from the product can be achieved by the use of PMHS.
- Motoyama, Yukihiro,Aoki, Masaharu,Takaoka, Naoki,Aoto, Ryuta,Nagashima, Hideo
-
supporting information; experimental part
p. 1574 - 1576
(2009/09/06)
-
- One-step deprotonation route to zinc amide and ester enolates for use in aldol reactions and Negishi couplings
-
Simple amides and esters are conveniently deprotonated by Zn(tmp)2 (tmp = 2,2,6,6-tetramethylpiperidinyl anion) to generate Zn enolates. Enolates formed by this method are suitable for use in aldol reactions that tolerate base-sensitive functional groups. Additionally, the Zn enolates are readily coupled with aryl bromides using typical Pd-catalyzed coupling methods.
- Hlavinka, Mark L.,Hagadorn, John R.
-
p. 5049 - 5053
(2007/10/03)
-
- Radical allylation, vinylation, alkynylation, and phenylation reactions of α-halo carbonyl compounds with organoboron, organogallium, and organoindium reagents
-
Allylic gallium and indium reagents are found to mediate radical allylation reactions of α-iodo or α-bromo carbonyl compounds. Treatment of benzyl bromoacetate with allylgallium, prepared from allylmagnesium chloride and gallium trichloride, in the presence of triethylborane provided benzyl 4-pentenoate in excellent yield. Addition of water as a co-solvent improved the yields of allylated products. Allylic indium reagents are also useful and can replace the gallium reagents. A diallylborane reagent can allylate an α-iodo ester in good yield. Alkenylation reactions of α-halo carbonyl compounds with alkenylindium proceeded via a radical process in the presence of triethylborane. Unactivated alkene moieties and styryl groups were introduced by this method. The carbon-carbon double bond geometry of the alkenylindiums was retained during the alkenylation. Preparation of an alkenylindium via a hydroindation of 1-alkyne and subsequent radical alkenylation established an efficient one-pot strategy. Radical alkynylations and phenylations with organoindium reagents are disclosed herein.
- Takami, Kazuaki,Usugi, Shin-Ichi,Yorimitsu, Hideki,Oshima, Koichiro
-
p. 824 - 839
(2007/10/03)
-
- On the Synthesis and Basicity of 1,3-Diaminoisoquinolines
-
A series of 6- and 7-substituted derivatives of 1,3-diaminoisoquinoline were synthesized by the reaction of N,N-diethylarylacetamides with POCl 3 and then with N,N-dimethylcyanamide. The products were identified by means of spectroscopic methods and their pKa dissociation constants were determined.
- Zielinski, Wojciech,Kudelko, Agnieszka
-
p. 403 - 409
(2007/10/03)
-
- Niobium pentachloride promoted conversion of carboxylic acids to carboxamides: Synthesis of the 4-aryl-1,2,3,4-tetrahydroisoquinoline alkaloid structures
-
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.
-
p. 272 - 276
(2007/10/03)
-
- Metallic bismuth and aluminium: New and efficient catalysts for the preparation of various amides
-
A new and efficient method for the preparation of various amides has been achieved by a simple reaction of an acid chloride with primary and secondary amines in the presence of bismuth or aluminium powder in anhydrous toluene.
- Gadhwal, Sunil,Sandhu, Jagir S.
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p. 257 - 259
(2007/10/03)
-
- Spectroscopy and absolute reactivity of ketenes in acetonitrile studied by laser flash photolysis with time-resolved infrared detection
-
Laser flash photolysis with time-resolved infrared detection of transients (LFP-TRIR) has been used to study the IR spectroscopy and reactivity of a number of substituted ketenes, prepared by the 308-nm photolysis of α-diazocarbonyl precursors in acetonitrile solution at room temperature. The correlation of the experimental ketene asymmetric stretching frequency to the Swain-Lupton field (F) and resonance (R) effect substituent parameters was unsatisfactory, whereas the correlation to the inductive substituent parameter (σ1) of Charton gave excellent results. This suggests that the asymmetric stretching frequency of substituted ketenes depends mainly on the inductive (i.e., field) effect of the substituents. The mechanism and kinetics of the reactions of these ketenes with various amines in acetonitrile were also studied. An intermediate species identified as either zwitterionic ylide or amide enol formed in the nucleophilic addition of the secondary amine to the C(α) of the ketene is observed by TRIR. The decay of this species is assisted by the amine and is concomitant with the formation of an amide, the final product of the reaction. Our kinetic data on ketene amine reactions show a general trend, indicating a much higher reactivity (ca. 3 orders of magnitude difference in the corresponding rate constants) of secondary amines compared with that of tertiary amines. Secondary diethylamine shows reactivity similar to those observed for primary amines, while secondary piperidine seems to be, in general, somewhat more reactive. The observed trend is rationalized in terms of the steric effects exerted by both amine and ketene substituents. Our data on para-substituted phenyl ketenes provide support for the negative charge development on the ketene moiety in the transition state, with electron-withdrawing substituents accelerating and electron-releasing substituents slowing down the addition reaction.
- Wagner, Brian D.,Arnold, Bradley R.,Brown, Gerald S.,Lusztyk, Janusz
-
p. 1827 - 1834
(2007/10/03)
-
- Ligand exchange reaction of sulfoxides in organic synthesis: A versatile procedure for one-carbon homologation of methylesters to esters, thioesters, carboxylic acids and amides
-
A novel two-step procedure for one-carbon homologation of methylesters to esters, thioesters, carboxylic acids and amides is described. Methylesters are reacted with lithium carbanion of chloromethyl phenyl sulfoxide to give α-chloro α-sulfinyl ketones in 70 to 90% yields. Potassium enolate of the α-chloro α-sulfinyl ketone was treated with tert-butyllithium at -78°C to give alkynolate via alkylidene carbenoid. This intermediate was treated with alcohols, thioles, 5% aqueous NaOH, and amine hydrochlorides to afford one-carbon homologated esters, thioesters, carboxylic acids and amides, respectively, in good to excellent yields.
- Satoh, Tsuyoshi,Unno, Hideaki,Mizu, Yasuhiro,Hayashi, Yasumasa
-
p. 7843 - 7854
(2007/10/03)
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- Phase-transfer catalyzed N-ethylation of N-ethyl-2-phenylacetamide
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Phase-transfer catalyzed N-ethylations of N-ethyl-2-phenylacetamide (EPA) in the presence of powdered KOH (solid-liquid system) have been carried out in order to establish the effect of catalyst structure on the reaction. The formation of O- and C-products of alkylation is monitored. The effect of temperature on N-alkylation as well as on the rearrangement of O- to N-product of alkylation has been investigated. The influence of the structure of the quaternary ammonium cation (quat) and the anion type on the yield of the N-ethylation product is also discussed. A suitable mechanism for the phase-transfer catalysed reaction is suggested.
- Mijin, Du?an ?.,Mi?i?-Vukovi?, Milica M.,Stojanovi?, Nade?da D.,Petrovi?, Slobodan D.
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p. 1201 - 1204
(2007/10/03)
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- Reactions of acyl nitroso compounds with amines: Production of nitroxyl (HNO) with the preparation of amides
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Oxidation of hydroxamic acids in the presence of amines generates nitrous oxide (N2O) and the corresponding amide. The identification of N2O suggests the intermediacy of nitroxyl (HNO). Retro-Diels Alder dissociation of cyclopentadiene-acyl nitroso compound cycloadducts releases N2O with amide formation.
- Atkinson, Robert N.,Storey, Bernadette M.,King, S. Bruce
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p. 9287 - 9290
(2007/10/03)
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- Substituent Effects on the CC Bond Strength, 17. - Formation and Stability of α-Carbamoylbenzyl Radicals
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Products and kinetics of the homolytic thermolyses reactions of the three tertiary amides 6a-c of 2,3,3-triphenylpropanoic acid were studied in solution.The steric effects on the C-C bond homolysis processes were evaluated from MM2 calculations.Taking this into account, we deduced radical stabilization enthalpies RSE for the α-carbamoylbenzyl radicals 3a-c from the activation enthalpies ΔH(excit.) . - Key Words: Bond cleavage, C-C kinetics of / Radicals, stability of
- Zueffle, Stephan,Beckhaus, Hans-Dieter,Ruechardt, Christoph
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p. 877 - 880
(2007/10/02)
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- THE CONVERSION OF CARBOXYLIC ACIDS TO AMIDES VIA TIN(II) REAGENTS
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Unsymmetrical tin(II) amides can be generated, in situ, by adding one equivalent of an amine to bis(bistrimethylamino) tin, Sn2.Treatment of carboxylic acids with these tin(II) reagents derived from alkyl or aryl amines results in smooth conversion to the corresponding N-alkyl or N-aryl amides.
- Burnell-Curty, Cynthia,Roskamp, Eric J.
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p. 5193 - 5196
(2007/10/02)
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- Tin(II) Amides: New Reagents for the Conversion of Esters to Amides
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Mixed tin(II) amides are generated, in situ, via addition of aliphatic amines to Sn2.Condensation of these reagents with esters yields amides.
- Wang, Wei-Bo,Roskamp, Eric J.
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p. 6101 - 6103
(2007/10/02)
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- Direct Aminolysis of Nonactivated and Thermally Unstable Esters at High Pressure
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The preparation of the amides 3 from a wide variety of nonactivated esters 1 and secondary amines 2 has been achieved at 8 kbar and around 45 deg C; scope and limitations are discussed.The method was also successfully applied for the aminolysis of alkyl 2-arylsulfinylacetates 7 that are relatively sensitive to heat. - Key Words: Aminolysis/ High-pressure synthesis
- Matsumoto, Kiyoshi,Hashimoto, Shiro,Uchida, Takane,Okamoto, Tadashi,Otani, Shinichi
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p. 1357 - 1364
(2007/10/02)
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- GENERATION AND REACTIONS OF CARBANIONS FROM DIALKYLAMINO(METHYLTHIO)ACETONITRILES
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Dialkylamino(methylthio)acetonitriles 1 have been prepared by two independent pathways.The carbanions generated from 1 in various base/solvent systems reacted with alkyl halides or electrophilic alkenes to give unstable products 2 and 5 respectively.These products were transformed into amides 3 or acids 4 and 6.On the other hand, carbanions from 1 with ethyl maleinate or ω-nitrostyrene afforded products of aliphatic vicarious nucleophilic substitution 7, while with 1-nitronaphthalene, the product of aromatic vicarious nucleophilic substitution 8.
- Jonczyk, Andrzej,Owczarczyk, Zbyslaw,Makosza, Mieczyslaw,Winiarski, Jerzy
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p. 303 - 310
(2007/10/02)
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