- Switchable Imine and Amine Synthesis Catalyzed by a Well-Defined Cobalt Complex
-
Switchable imine and amine synthesis catalyzed by a tripodal ligand-supported well-defined cobalt complex is presented herein. A large variety of primary alcohols and amines were selectively converted to imines or amines in good to excellent yields. It is discovered that the base plays a crucial role on the selectivity. A catalytic amount of base leads to the imine formation, while an excess loading of base results in the amine product. This strategy on product selectivity also strongly depends on the organometallic catalysts in use. We expect that the present study could provide useful insights toward selective organic synthesis and catalyst design.
- Paudel, Keshav,Xu, Shi,Hietsoi, Oleksandr,Pandey, Bedraj,Onuh, Chuka,Ding, Keying
-
supporting information
p. 418 - 426
(2021/02/01)
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- A highly efficient Co-based catalyst fabricated by coordination-assisted impregnation strategy towards tandem catalytic functionalization of nitroarenes with various alcohols
-
A well-defined hexamethylenetetramine (abbreviated as HMTA) based two-dimensional (2D) MOFs metalloligand (termed Zn-HMTA), with free uncoordinated tertiary amine groups, has been synthesized via solution diffusion method for the first time. The crystal structure of 2D Zn-HMTA metalloligand was determined by the single crystal X-ray diffraction (SCXRD). The SCXRD and X-ray photoelectron spectroscopy (XPS) analyses have revealed that the 2D Zn-HMTA metalloligand is rich in- free tertiary amine groups, which are of strong coordination ability to transition metal ions (e.g. Ni2+, Co2+, Zn2+, Cu2+). As a result, a 2D bimetallic Co@Zn-HMTA MOFs was synthesized via coordination-assisted impregnation (CAI) strategy attributed to the unique feature of strong coordinated ability of free tertiary amine groups. Furthermore, a series of self-supported Co-ZnO-CN nanocatalysts were afforded upon the as-synthesized Co@Zn-HMTA MOFs served as a self-sacrificial template for pyrolysis at different temperatures. The optimized catalyst (termed as Co-ZnO@CN-CAI) demonstrated the excellent catalytic performance for hydrogenation-alkylation tandem reaction in comparison with the classic ZnO@CN composite (derived from Zn-HMTA MOFs) supported metallic Co catalyst (Co-ZnO@CN-IWI) prepared by incipient wetness impregnation method. Moreover, the kinetic study was also performed to confirm that the alkylation is the rate-determining step in the hydrogenation-alkylation tandem reaction. The origin of enhanced catalytic performance of Co-ZnO@CN-CAI and the role of Co@Zn-HMTA MOFs precursor have been explored by way of various characterizations, e.g. HADDF-STEM-EDS, SEM-EDS, 13C MAS NMR, XRD, Raman and XPS, etc. It is anticipated that the prepared low-cost and easily prepared 2D Zn-HMTA metalloligand will become a general template for synthesis of highly self-supported catalysts with coordination-assisted impregnation strategy (CAI) for various catalytic reactions.
- Li, Guangming,Li, Jingfang,Li, Weizuo,Li, Xuewei,Li, Zhibin,Mao, Guijie,She, Wei,Wang, Jing
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p. 462 - 474
(2021/11/11)
-
- Bidentate geometry-constrained iminopyridyl nickel-catalyzed synthesis of amines or imines via borrowing hydrogen or dehydrogenative condensation
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The efficient Ni-catalyzed N-alkylation of various anilines with alcohols via borrowing hydrogen is reported using a bidentate geometry-constrained iminopyridyl nickel complex as the catalyst. Substituted benzylic alcohols and short/long chain aliphatic alcohols could be applied as the alkylation sources to couple with aromatic and heteroaromatic amines to give a diverse set of N-alkylation outcomes in moderate to excellent yields. The nickel catalytic system was also suitable for aliphatic amines, selectively delivering the corresponding imines via an acceptorless dehydrogenative condensation strategy.
- Jiang, Yong,Hu, Miao,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan,Jin, Liqun
-
supporting information
(2020/11/27)
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- C–N Cross-coupling Reactions of Amines with Aryl Halides Using Amide-Based Pincer Nickel(II) Catalyst
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Abstract: An approach to C–N cross-coupling reactions of aryl halides with amines in the presence of an amide-based pincer nickel(II) catalyst (2) is described. For 3?h reactions at 110?°C with 0.2?mol% catalyst, aryl bromides gave higher turnover numbers (TON) than the corresponding chlorides or iodides. Both primary and secondary amines could be used with the former giving higher TON. However, sterically hindered amines showed lower TON. In elucidating the mechanism of this nickel complex-catalyzed C–N cross coupling reaction it was found that the rate of reaction was unchanged in the presence of radical quenchers and a plausible Ni(I)–Ni(III) pathway is proposed. Graphic Abstract: [Figure not available: see fulltext.]Nickel pincer catalyst proved to be excellent catalyst for the C-N cross-coupling reaction with the high turnover number (TON) for 1° and 2° amines and different nonactivated aryl halides under optimum conditions.
- Albkuri, Yahya M.,RanguMagar, Ambar B.,Brandt, Andrew,Wayland, Hunter A.,Chhetri, Bijay P.,Parnell, Charlette M.,Szwedo, Peter,Parameswaran-Thankam, Anil,Ghosh, Anindya
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p. 1669 - 1678
(2019/12/27)
-
- Transfer Hydrogenation of Ketones and Imines with Methanol under Base-Free Conditions Catalyzed by an Anionic Metal-Ligand Bifunctional Iridium Catalyst
-
An anionic iridium complex [Cp*Ir(2,2′-bpyO)(OH)][Na] was found to be a general and highly efficient catalyst for transfer hydrogenation of ketones and imines with methanol under base-free conditions. Readily reducible or labile substituents, such as nitro, cyano, and ester groups, were tolerated under present reaction conditions. Notably, this study exhibits the unique potential of anionic metal-ligand bifunctional iridium catalysts for transfer hydrogenation with methanol as a hydrogen source.
- Han, Xingyou,Li, Feng,Liu, Peng,Wang, Rongzhou,Xu, Jing
-
p. 2242 - 2249
(2020/03/13)
-
- Room temperature N-heterocyclic carbene manganese catalyzed selective N-alkylation of anilines with alcohols
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The first example of room temperature non-noble metal homogeneous system catalyzed selective N-alkylation of anilines with alcohols by a bis-NHC manganese complex is presented. This system was applied to a large range of alcohols and anilines, including biologically relevant motifs and challenging methanol. Experimental and computational studies suggest an outer-sphere mechanism for this NHC-Mn system.
- Huang, Ming,Li, Yukui,Li, Yinwu,Liu, Jiahao,Shu, Siwei,Liu, Yan,Ke, Zhuofeng
-
supporting information
p. 6213 - 6216
(2019/06/07)
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- A Highly Active PN3 Manganese Pincer Complex Performing N-Alkylation of Amines under Mild Conditions
-
A highly active Mn(I) catalyst based on a nonsymmetric PN3-ligand scaffold for the N-alkylation of amines with alcohols utilizing the borrowing hydrogen methodology is reported. A broad range of anilines and the more challenging aliphatic amines were alkylated with primary and secondary alcohols. Moreover, the combination of low catalyst loadings and mild reaction conditions provides high efficiency for this atom-economic transformation.
- Homberg, Leonard,Roller, Alexander,Hultzsch, Kai C.
-
supporting information
(2019/05/07)
-
- Switching the N-Alkylation of Arylamines with Benzyl Alcohols to Imine Formation Enables the One-Pot Synthesis of Enantioenriched α-N-Alkylaminophosphonates
-
The selective N-alkylation of anilines with benzylic alcohols can be switched in favor of the dehydrogenative condensation process using the nitrile-ligated Kn?lker's complex by conducting the reaction either in a closed system under inert conditions, or in an open system in air. The selective formation of imines, containing reactive C=N bonds, provides an opportunity towards further functionalization. Indeed, a one-pot three-component condensation of alcohols, amines and phosphites, promoted by an iron-based Kn?lker-type complex in combination with a chiral BINOL-based phosphoric acid, provides access to enantioenriched α-N-alkylaminophosphonates.
- Hofmann, Natalie,Hultzsch, Kai C.
-
supporting information
p. 3105 - 3111
(2019/06/08)
-
- Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
-
A ruthenium(II)-catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2-methylallyl)2(COD)], 1,1,1-tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction-sensitive. The choice of hydrogen source and acid co-catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway. (Figure presented.).
- Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
-
supporting information
p. 3800 - 3806
(2019/07/12)
-
- Iridium(III)- benzoxazolyl and benzothiazolyl phosphine ligands catalyzed versatile alkylation reactions with alcohols and the synthesis of quinolines and indole
-
A series of benzoxazolyl and benzothiazolyl phosphine ligands 4a-4g were synthesized and characterized, which prepared from commercially available 2-aminophenol/2-aminobenzenethiol and 2-bromobenzaldehyde via cyclization and phosphination. The representative ligands 4c and 4e were determined by single-crystal X-ray diffraction. The corresponding iridium complexes could be generated in situ when [Cp*IrCl2]2 (Cp* = pentamethylcyclopentadienyl) encountered ligands. The molecular structures of complexes 5c and 5e were crystallographically characterized. The dihedral angles of N (1)-C (1)-C (8)-C (9) showed an increasing twist compared with the corresponding ligand. The iridium (III) catalysts were screened, [Cp*IrCl2]2/4a proved to be the optimal catalyst, which exhibited efficient catalytic activity toward versatile alkylations including ketones, secondary alcohols and amines with primary alcohols. Additionally, the synthesis of quinolines from ketones with 2-aminobenzyl alcohol by intermolecular cyclization and indole from 2-(2-aminophenyl)ethanol by intramolecular cyclization were achieved under the optimized conditions.
- Huang, Shuang,Wu, Si-Peng,Zhou, Quan,Cui, He-Zhen,Hong, Xi,Lin, Yue-Jian,Hou, Xiu-Feng
-
-
- N-Alkylation of Aniline and Its Derivatives by Alcohols in the Presence of Copper Compounds
-
N-Alkyl- and N,N-dialkyl-substituted anilines were obtained in the reaction of aniline and its derivatives with primary and secondary alcohols in the presence of catalysts CuCl2·2H2O, CuBr2 and halomethanes as promoters.
- Bayguzina,Musina, Ch. F.,Khusnutdinov
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p. 1652 - 1659
(2019/02/12)
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- AuPd?Fe3O4 Nanoparticle Catalysts for Highly Selective, One-Pot Cascade Nitro-Reduction and Reductive Amination
-
Exceedingly chemoselective preparation of secondary amines from the cascade reaction of nitro reduction followed by reductive amination of the resulting amine with an aldehyde through the use of bimetallic AuPd alloy nanoparticle catalyst is described. We prepared a AuPd alloy nanocatalyst supported on Fe3O4 in gram scale without calcination. One pot synthesis of a number of secondary amines was achieved from a variety of nitroarenes and aryl or alkyl aldehydes under 1 atm of H2 at room temperature. No N-debenzylation was observed in the case of the reactions involving aryl aldehydes, which is often observed in the reductive amination catalysed by a transition metal catalyst such as palladium. We also accomplished efficient one-pot synthesis of a number of N-aryl substituted isoindolinone derivatives from 1-formylbenzoic acid and several nitroarenes using the same reaction conditions. Furthermore, thanks to the magnetic property of the Fe3O4 support, the AuPd?Fe3O4 NPs could be easily separated and reused up to 20 times without the loss of its catalytic activity. (Figure presented.).
- Cho, Ahra,Byun, Sangmoon,Kim, B. Moon
-
supporting information
p. 1253 - 1261
(2018/02/21)
-
- Lewis Base-Boryl Radicals Enabled the Desulfurizative Reduction and Annulation of Thioamides
-
A new protocol for radical transformations of thioamides promoted by Lewis base-boryl radicals is reported. The desulfurizative reduction to access organic amines was enabled utilizing 4-dimethylaminopyridine-BH3 as the boryl radical precursor and PhSH as the polarity reversal catalyst. Alternatively, the chain process for unsaturated thioamides was switched to an annulation reaction using N-heterocyclic carbene-BH3 as the boryl radical precursor and sterically bulky Ph3CSH as the catalyst, allowing for the construction of N-heterocyclic and carbocyclic skeletons.
- Yu, You-Jie,Zhang, Feng-Lian,Cheng, Jie,Hei, Jing-Hao,Deng, Wei-Ting,Wang, Yi-Feng
-
supporting information
p. 24 - 27
(2018/01/17)
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- Regiospecific N-Arylation of Aliphatic Amines under Mild and Metal-Free Reaction Conditions
-
A transition metal-free N-arylation of primary and secondary amines with diaryliodonium salts is presented. Both acyclic and cyclic amines are well tolerated, providing a large set of N-alkyl anilines. The methodology is unprecedented among metal-free methods in terms of amine scope, the ability to transfer both electron-withdrawing and electron-donating aryl groups, and efficient use of resources, as excess substrate or reagents are not required.
- Purkait, Nibadita,Kervefors, Gabriella,Linde, Erika,Olofsson, Berit
-
supporting information
p. 11427 - 11431
(2018/08/28)
-
- Fe(CrO2)2-catalyzed, photoactivated oxidative one-pot tandem synthesis of substituted quinolines from primary alcohols and arylamines
-
[Figure not available: see fulltext.] A one-pot tandem synthesis of substituted quinolines involving selective catalytic oxidation of primary alcohols to the corresponding aldehydes and their subsequent condensation with arylamines has been developed. Fe(CrO2)2 has been used as a catalyst, and oxidation has been performed with aqueous H2O2. To accelerate the catalytic oxidation of alcohols, photoactivation method has been applied.
- Makhmutov, Aynur R.,Mustafin, Akhat G.,Usmanov, Salavat M.
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p. 369 - 374
(2018/05/28)
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- Method for preparing secondary aromatic amine or tertiary aromatic amine by conducting amination on aryl halide or alkyl halide
-
The invention discloses a method for preparing secondary aromatic amine or tertiary aromatic amine by conducting amination on aryl halide or alkyl halide. That is to say, the alkyl halide or the arylhalide and organic amine are mixed according to a certain ratio, and under light irradiation, C-N coupling reaction is carried out, so that a corresponding target product is generated for preparing the secondary amine or the tertiary amine. Compared with existing synthesis technologies, the method has the advantages that the aryl halide or the alkyl halide which is cheap and easy to get is selected as a reaction substrate, the method has good universality for different organic amine separately, moreover, the product selectivity is high, and separation and purification are easy; moreover, the synthesis method does not need to be conducted under severe conditions of high temperature and the like, a green and sustainable light source is adopted as driving force, the atom economy is high, andthe method has wide application prospects.
- -
-
Paragraph 0029-0035; 0160; 0120; 0121; 0162
(2019/01/14)
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- An Efficient Homogenized Ruthenium(II) Pincer Complex for N-Monoalkylation of Amines with Alcohols
-
An ionic 2,6-bis(imidazo[1,2-α]pyridin-2-yl)pyridine-based N^N^N pincer ruthenium(II) complex exhibited high efficiency in the C–N bond formation between amines and alcohols by the “borrowing hydrogen” (BH) or “hydrogen autotransfer” (HA) concept. The synthetic protocol selectively generated monoalkylated amines without formation of tertiary amines during the reaction. The unique selectivity enabled the formation of symmetrically and asymmetrically substituted diamines. This methodology features several advantages including a low catalyst loading (as low as 0.5 mol-%), a short reaction time (as short as 2 h), and excellent N-monoalkylation selectivity.
- Yang, Fa-Liu,Wang, Ying-Hui,Ni, Yong-Feng,Gao, Xiang,Song, Bing,Zhu, Xinju,Hao, Xin-Qi
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p. 3481 - 3486
(2017/07/04)
-
- Method for reducing thioamide compound
-
The invention provides a method for reducing a thioamide compound. The method comprises: at 80 DEG C and under nitrogen protection, taking thioamide as a substrate, adding ditert-butoxyazide (TBHN) and 4-dimethylamino pyridine borane complex (DMAP-BH3) as radical initiators, adding a catalytic amount of thiophenol, and performing stirring in acetonitrile for a proper time to obtain corresponding amine. The same conversion can be achieved by taking triethylborane/oxygen as an initiator at 25 DEG C. The reaction is non-toxic, and is mild in reaction condition, convenient to operate, good in function group tolerance, short in reaction time, and high in efficiency.
- -
-
Paragraph 0025-0028
(2017/10/07)
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- Boron Lewis Acid Promoted Ruthenium-Catalyzed Hydrogenation of Amides: An Efficient Approach to Secondary Amines
-
The hydrogenation of amides to amines has been developed by using the catalyst [Ru(H)2(CO)(Triphos)] (Triphos=1,1,1-tri(diphenylphosphinomethyl)ethane) and catalytic boron Lewis acids such as B(C6F5)3 or BF3?Et2O as additives. The reaction provides an efficient method for the preparation of secondary amines from amides in good yields with high selectivity.
- Yuan, Ming-Lei,Xie, Jian-Hua,Zhou, Qi-Lin
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p. 3036 - 3040
(2016/10/11)
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- Transfer hydrogenative reductive amination of aldehydes in aqueous sodium formate solution
-
A practical direct reductive amination reaction of aldehydes in aqueous sodium formate solution which produces amines in good yields under mild conditions is described. The amount and strength of the acid additives were critical factors to affect the reaction selectivities. This reductive amination method has great application potential for the synthesis of amine products given the mild conditions, short reaction time, the use of water as a solvent, and the use of benign hydrogen sources.
- Zhu, Mengping
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p. 509 - 511
(2016/01/12)
-
- Palladium nanoparticles stabilised by cinchona-based alkaloids in glycerol: Efficient catalysts for surface assisted processes
-
Palladium nanoparticles (PdNPs) were synthesised and fully characterised, both in solution and the solid state, using naturally-occurring cinchona-based alkaloids in neat glycerol. These nano-systems were stable under reaction conditions, finding applications in hydrogenation and hydrodehalogenation processes, as a result of their surface-like behaviour. Their reactivity was improved in relation to that involving PdNPs stabilised by phosphines and also by Pd/C as a heterogenous catalyst, mainly in terms of recyclability. In particular, the colloidal palladium catalyst stabilised by quinidine was highly efficient to promote the hydrodechlorination of aromatic compounds under low dihydrogen pressure. These original catalysts found applications in the synthesis of secondary and tertiary amines including N-substituted anilines, by means of one-pot tandem Pd-catalysed methodologies under smooth conditions. In all of these processes, glycerol performed a crucial function as a liquid support for the immobilisation of nanoparticle-based catalysts, allowing both the stabilisation of the nano-catalysts and easy recycling of the catalytic phase.
- Reina,Pradel,Martin,Teuma,Gómez
-
p. 93205 - 93216
(2016/10/11)
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- Cobalt-Catalyzed Synthesis of Aromatic, Aliphatic, and Cyclic Secondary Amines via a "hydrogen-Borrowing" Strategy
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The replacement of precious metals with inexpensive, less toxic, and earth-abundant elements in typical noble-metal-mediated organic transformations is a major goal in current synthetic chemistry and industries. The metal-catalyzed N-alkylation of amines with other amines through a "hydrogen-borrowing" principle represents a green and atom-economical reaction for the synthesis of secondary amines. However, catalysts developed thus far that are effective for this process remain quite scarce and are only limited to a few ruthenium and iridium complexes. In this work, we present a cobalt-catalyzed selective alkylation of amines with amines to synthesize a large variety of secondary amines. A range of amine substrates have been converted to the corresponding products through hetero- or homocoupling between amines. Cyclic sec-amines are also achieved from diamine precursors as rare examples.
- Yin, Zhiwei,Zeng, Haisu,Wu, Jing,Zheng, Shengping,Zhang, Guoqi
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p. 6546 - 6550
(2016/10/14)
-
- Development of Quinoline-2,4(1H,3H)-diones as Potent and Selective Ligands of the Cannabinoid Type 2 Receptor
-
The cannabinoid type 2 receptors (CB2Rs) play crucial roles in inflammatory diseases. There has been considerable interest in developing potent and selective ligands for CB2R. In this study, quinoline-2,4(1H,3H)-dione analogs have been designed, synthesized, and evaluated for their potencies and binding properties toward the cannabinoid type 1 receptor (CB1R) and CB2R. C5- or C8-substituted quinoline-2,4(1H,3H)-diones demonstrate CB2R agonist activity, while the C6- or C7-substituted analogs are antagonists of CB2R. In addition, oral administration of 21 dose-dependently alleviates the clinical symptoms of experimental autoimmune encephalomyelitis in a mouse model of multiple sclerosis and protects the central nervous system from immune damage. Furthermore, the interaction modes predicted by docking simulations and the 3D-QSAR model generated with CoMFA may offer guidance for further design and modification of CB2R modulators.
- Han, Shuang,Zhang, Fei-Fei,Qian, Hai-Yan,Chen, Li-Li,Pu, Jian-Bin,Xie, Xin,Chen, Jian-Zhong
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p. 5751 - 5769
(2015/08/24)
-
- An efficient catalytic reductive amination: A facile one-pot access to 1,2-dihydropyrrolo[3,4-b]indol-3(4H)-ones by using B(C 6 F 5 ) 3 /NaBH 4
-
An efficient combination of B(C6F5)3 and NaBH4 was developed for direct reductive amination of aldehydes. A wide range of functional groups such as ester, nitro, nitrile, halogen, alkene, heterocycles were tolerated. Also, acid sensitive protecting groups like TBDMS and TBDPS were not affected. In addition, the present methodology was extended for tandem amination-amidation of 3-formyl-indole-2-carboxylic acids with substituted anilines to afford 1,2-dihydropyrrolo[3,4-b]indol-3(4H)-ones. [Figure not available: see fulltext.]
- Nagarsenkar, Atulya,Prajapti, Santosh Kumar,Babu, Bathini Nagendra
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p. 711 - 716
(2015/06/17)
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- Synthesis, structures of benzoxazolyl iridium(III) complexes, and applications on C-C and C-N bond formation reactions under solvent-free conditions: Catalytic activity enhanced by noncoordinating anion without silver effect
-
Several new bisbenzoxazolyl iridium(III) complexes have been synthesized and characterized through X-ray crystallography. These complexes exhibit excellent catalytic activity in C-C and C-N bond formation reactions from the alkylation of amine with amine, amine with alcohol, ketone with alcohol, and alcohol with alcohol through a borrowing hydrogen reaction. Moreover, these iridium(III) complexes are effective catalysts for the alkylation of amine with alcohol and ketone with alcohol under solvent-free conditions. The catalytic activity of these complexes is greatly enhanced by noncoordinating, while the experiments have excluded the possibility of a "silver effect" (bimetallic catalysis or silver-assisted metal catalysis) from the experiments.
- Wang, Dawei,Zhao, Keyan,Xu, Chongying,Miao, Hongyan,Ding, Yuqiang
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p. 3910 - 3918
(2014/12/12)
-
- An efficient homogeneous gold(I) catalyst for N-alkylation of amines with alcohols by hydrogen autotransfer
-
A new and highly efficient homogeneous [Ph3PAuCl]/AgOTf catalytic system was developed in N-alkylation reaction of primary amines with alcohols through a hydrogen autotransfer process. This Au(I) catalytic system shows excellent selectivity for mono-alkylation of primary amines with benzyl alcohol under moderate temperature of 100 °C (only secondary amines as product). The possible mechanism of this hydrogen autotransfer reaction with the catalytic system was proposed.
- Yang, Hongwei,Mao, Rongfang,Luo, Cuicui,Lu, Chunxu,Cheng, Guangbin
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p. 8829 - 8835
(2015/03/05)
-
- Direct N-alkylation of amines with alcohols using AlCl3 as a Lewis acid
-
A substitution reaction of amines with alcohols for N-alkylated amines has been developed using inexpensive AlCl3 without any ligand or additive. Either aromatic or aliphatic amines and primary or secondary alcohols perform the AlCl3-mediated reaction smoothly to afford various N-alkylated amines in satisfactory yields.
- Li, Ya-Qiong,Chen, Yun-Bin,Huang, Zhi-Zhen
-
p. 1540 - 1544
(2015/01/09)
-
- Ruthenium-catalyzed direct reductive amination in HCOOH/NEt3 mixture
-
A one-pot direct reductive amination of aldehydes with primary and secondary amines using Noyori's catalyst (η 6-arene)Ru(H)TsDPEN in neat HCOOH/NEt3 mixture has been developed. The catalyst formed in situ allows full conversion of aldehydes with high selectivities towards the desired amine products within hours or even minutes at room temperature. For aromatic aldehydes, both 5:2 and 5:3 HCOOH/NEt3 mixtures prove to be suitable reaction media, with the former affording higher selectivities while the latter leading to much faster reaction rates. For aliphatic aldehydes, the 5:3 HCOOH/NEt3 mixture gives much higher selectivities due to the minimal loss from aldol condensation. This method has great application potential for the synthesis of amine products given the mild conditions. Graphical Abstract: [Figure not available: see fulltext.]
- Zhu, Mengping
-
p. 1568 - 1572,5
(2014/10/15)
-
- Chemoselective deprotection of N-allylic amines using DDQ
-
A highly chemoselective and simple method for the deprotection of N-allylic amines using DDQ has been developed. The use of DDQ in dichloromethane-water provides a mild and efficient one-step deallylation of a wide variety of orthogonally protected tertiary amine derivatives.
- Kumar, Pradeep,Cherian, Shijo K.,Jain, Ruchi,Show, Krishanu
-
supporting information
p. 7172 - 7176
(2015/01/09)
-
- Solid base catalyzed highly efficient N-alkylation of amines with alcohols in a solvent-free system
-
Different from any other catalytic systems containing transition metals and additives, sodium hydroxide itself was found to be a unique and effective catalyst for the solvent-free synthesis of the secondary amines via the N-alkylation of amines with alcohols. For the reaction of aniline with benzyl alcohol, 99.6 mol% conversion of aniline and 99.5% selectivity of the product were achieved under optimal conditions. Also, high conversion and selectivity could be acquired for the N-alkylations of various amines with alcohols, implying the universality of this methodology. Mechanistic studies revealed that this novel reaction most possibly proceeds with a base-catalyzed mechanism.
- Lu,Sun,Wei,Peng,Zhou,Xia
-
-
- Selective N-alkylation of amines using nitriles under hydrogenation conditions: Facile synthesis of secondary and tertiary amines
-
Nitriles were found to be highly effective alkylating reagents for the selective N-alkylation of amines under catalytic hydrogenation conditions. For the aromatic primary amines, the corresponding secondary amines were selectively obtained under Pd/C-catalyzed hydrogenation conditions. Although the use of electron poor aromatic amines or bulky nitriles showed a lower reactivity toward the reductive alkylation, the addition of NH4OAc enhanced the reactivity to give secondary aromatic amines in good to excellent yields. Under the same reaction conditions, aromatic nitro compounds instead of the aromatic primary amines could be directly transformed into secondary amines via a domino reaction involving the one-pot hydrogenation of the nitro group and the reductive alkylation of the amines. While aliphatic amines were effectively converted to the corresponding tertiary amines under Pd/C-catalyzed conditions, Rh/C was a highly effective catalyst for the N-monoalkylation of aliphatic primary amines without over-alkylation to the tertiary amines. Furthermore, the combination of the Rh/C-catalyzed N-monoalkylation of the aliphatic primary amines and additional Pd/C-catalyzed alkylation of the resulting secondary aliphatic amines could selectively prepare aliphatic tertiary amines possessing three different alkyl groups. According to the mechanistic studies, it seems reasonable to conclude that nitriles were reduced to aldimines before the nucleophilic attack of the amine during the first step of the reaction.
- Ikawa, Takashi,Fujita, Yuki,Mizusaki, Tomoteru,Betsuin, Sae,Takamatsu, Haruki,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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supporting information; experimental part
p. 293 - 304
(2012/02/01)
-
- N-alkylation of amines with alcohols over alumina-entrapped Ag catalysts using the "borrowing hydrogen" methodology
-
Ag/Al2O3 catalysts were found to be highly active and selective in the N-alkylation of aniline with a variety of aromatic and linear alcohols. In the presence of a base, for example, Cs2CO3 or K3PO4 as promoter, high yields of secondary amines were obtained. The highest activity was found with 2.4 wt.% Ag/Al2O 3. The reaction involves the transient catalytic dehydrogenation of the alkylating alcohol to the corresponding carbonyl compound which then reacts spontaneously with the amine. In the final step, the hydrogen from the alcohol dehydrogenation step is transferred back to the imine, giving the secondary amine as the final product. With secondary amines, piperidine and pyrrolidine, the hemiaminal intermediate can undergo dehydrogenation as well as dehydration to give amides and amines, respectively. The heterogeneous nature of Ag/Al 2O3 allows for easy recovery and regeneration, which makes it an attractive system in the context of green and sustainable synthesis.
- Liu, Huihui,Chuah, Gaik-Khuan,Jaenicke, Stephan
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experimental part
p. 130 - 137
(2012/10/07)
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- Ruthenium-catalyzed one-pot aromatic secondary amine formation from nitroarenes and alcohols
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Beg, steal, or borrow: The synthesis of aromatic secondary amines has been developed using commercially available [Ru(acac)3]/dppe as the catalyst. Chlorobenzene solvent gave high selectivity, with only trace amounts of imine and tertiary amine observed.
- Liu, Yong,Chen, Wen,Feng, Chao,Deng, Guojun
-
supporting information; experimental part
p. 1142 - 1146
(2011/12/14)
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- Discovery of novel quaternary ammonium derivatives of (3R)-quinuclidinyl carbamates as potent and long acting muscarinic antagonists
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Novel quaternary ammonium derivatives of N,N-disubstituted (3R)-quinuclidinyl carbamates have been identified as potent M3 muscarinic antagonists with long duration of action in an in vivo model of bronchoconstriction. These compounds have also presented a high level of metabolic transformation (human liver microsomes). The synthesis, structure-activity relationships and biological evaluation of these compounds are reported.
- Prat, Maria,Buil, María Antonia,Fernández, Maria Dolors,Castro, Jordi,Monleón, Juan Manuel,Tort, Laia,Casals, Gaspar,Ferrer, Manuel,Huerta, Josep Maria,Espinosa, Snia,López, Manuel,Segarra, Victor,Gavald, Amadeu,Miralpeix, Montserrat,Ramos, Israel,Vilella, Dolors,González, Marisa,Córdoba, Mnica,Cárdenas, Alvaro,Antón, Francisca,Beleta, Jorge,Ryder, Hamish
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p. 3457 - 3461
(2011/06/24)
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- New iridium catalysts for the efficient alkylation of anilines by alcohols under mild conditions
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The synthesis of eight new iridium complexes containing anionic P,N ligands is described. These complexes have been investigated as catalysts for amine alkylation reactions, resulting in a highly active catalyst for the selective monoalkylation of anilines with primary alcohols, under mild reaction conditions. Nearly quantitative conversion was observed at 70 °C with a catalyst loading as low as 0.05 mol % iridium. Selective amine alkylation: The synthesis of eight new iridium complexes containing anionic P,N ligands (see image) is described. These new complexes were used as highly active catalysts for the selective monoalkylation of anilines with primary alcohols, and gave nearly quantitative conversion under mild reaction conditions.
- Michlik, Stefan,Kempe, Rhett
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experimental part
p. 13193 - 13198
(2011/02/24)
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- Single nucleotide-catalyzed biomimetic reductive amination
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We have successfully developed a single nucleotide (adenosine 5'-diphosphate)-catalyzed enantioselective direct reductive amination of aldehydes and ketones using a Hantzsch ester as reducing agent. The process is a simple, efficient and a real mimic of the NADH reduction approach for the synthesis of structurally diverse amines. This reaction is the first report demonstrating the ability of a single nucleotide as catalyst and one of the most genuine biomimetic reactions of organic chemistry.
- Kumar, Atui,Sharma, Siddharth,Maurya, Ram Awatar
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supporting information; experimental part
p. 2227 - 2232
(2010/11/24)
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- Rhodium(NHC)-catalyzed amination of aryl bromides
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(Figure Presented) A rhodium-catalyzed amination reaction of aryl halides with amines has been developed with the use of a N-heterocyclic carbene (NHC) ligand (I/Pr = 1,3-diisopropylimidazol-2-ylidene). The active metal species responsible for the reaction progress was identified. The developed procedure of the Rh-catalyzedW-arylation is convenient to carry out under mild reaction conditions displaying a wide range of substrate scope and high degree of functional group tolerance.
- Kim, Min,Chang, Sukbok
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supporting information; experimental part
p. 1640 - 1643
(2010/06/16)
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- C-N bond formation catalysed by CuI Bonded to polyaniline nanofiber
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Polyaniline nanofiber as a macroligand for the supported cuprous iodide catalyst (CuI-PANInf) has been developed for the coupling of aryl halides (including aryl chlorides) with aliphatic, aromatic, and N(H)-heterocyclic amines under ambient conditions (80 °C for aryl chlorides) has been developed. This simple and efficient method for coupling reactions is highly versatile, convenient, and also the catalyst can be used for several cycles with good-to-excellent yields.
- Arundhathi, Racha,Kumar, Desitti Chaitanya,Sreedhar, Bojja
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supporting information; experimental part
p. 3621 - 3630
(2010/08/20)
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- PALLADIUM CATALYSTS
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The invention relates to a particulate substance comprising a particulate porous support coupled to a palladium species. The palladium species may comprise palladium nanoclusters. The particulate substance may be used as a catalyst for conducting a carbon-carbon coupling reaction or a reduction.
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Page/Page column 16; 19
(2010/05/13)
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- HETEROCYCLIC DERIVATIVE HAVING INHIBITORY ACTIVITY ON TYPE-I 11 -HYDROXYSTEROID DEHYDROGENASE
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Disclosed is a compound which is useful as an 11β-hydroxysteroid dehydrogenase type 1 inhibitor. A compound represented by the formula: its pharmaceutically acceptable salt, or a solvate thereof, wherein X is O or S, a broken line and a wavy line represent the presence or the absence of a bond, (i) when a broken line represents the presence of a bond, a wavy line represents the absence of a bond, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, (ii) when a broken line represents the absence of a bond, a wavy line represents the presence of a bond, R1 and R4 are each independently hydrogen, halogen or the like, R2 and R3 are each independently hydrogen, halogen, cyano, hydroxy, carboxy, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like, and R5 and R6 are each independently hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl or the like.
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Page/Page column 134-135
(2010/08/07)
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- Design and synthesis of novel dihydroquinoline-3-carboxylic acids as HIV-1 integrase inhibitors
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Previously, we discovered linomide analogues as novel HIV-1 integrase (IN) inhibitors. Here, to make possible structure-activity relationships, we report on the design and synthesis of a series of substituted dihydroquinoline-3-carboxylic acids. The crystal structure of the representative compound 2c has also been solved. Among the eight new analogues, 2e showed a potency in inhibiting IN strand transfer catalytic activity similar to the reference diketo acid inhibitor L-731,988 (IC50 = 0.9 μM vs. 0.54 μM, for 2e and L-731,988, respectively). Furthermore, none of the compounds showed significant cytotoxicity in two tested cancer cell lines. These compounds represent an interesting prototype of IN inhibitors, potentially involved in a metal chelating mechanism, and further optimization is warranted.
- Sechi, Mario,Rizzi, Giuseppe,Bacchi, Alessia,Carcelli, Mauro,Rogolino, Dominga,Pala, Nicolino,Sanchez, Tino W.,Taheri, Laleh,Dayam, Raveendra,Neamati, Nouri
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experimental part
p. 2925 - 2935
(2009/09/05)
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- Palladium nanoclusters supported on propylurea-modified siliceous mesocellular foam for coupling and hydrogenation reactions
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This paper describes the synthesis, characterization and applications of palladium (Pd) nanoparticles supported on siliceous mesocellular foam (MCF). Pd nanoparticles of 2-3 nm and 4-6 nm were used in reactions involving molecular hydrogen (such as hydrogenation of double bonds and reductive amination), transfer hydrogenation of ketones and epoxides, and coupling reactions (such as Heck and Suzuki reactions). They successfully catalyzed all these reactions with excellent yield and selectivity. This heterogeneous catalyst was easily recovered by filtration, and recycled several times without any significant loss in activity and selectivity. The palladium leaching in the reactions was determined to be much less than the FDA-approved limit of 5 ppm. Furthermore, the catalyst can be stored and handled under normal atmospheric conditions. This immobilized catalyst allows for ease of recovery/reuse and minimization of waste generation, which are of great interest in the development of green chemical processes.
- Erathodiyil, Nandanan,Ooi, Samuel,Seayad, Abdul M.,Han, Yu,Lee, Su Seong,Ying, Jackie Y.
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experimental part
p. 3118 - 3125
(2009/04/08)
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- Direct reductive amination of carbonyl compounds with primary/secondary amines using recyclable water-soluble FeII/EDTA complex as catalyst
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Direct reductive amination of aliphatic, aromatic and heterocyclic carbonyl compounds with primary/secondary amines is reported with water-soluble FeII/EDTA complex as a catalyst using low-pressure molecular hydrogen in a biphasic media. The catalyst is highly selective, recyclable and is an excellent replacement for expensive noble metal catalysts or stoichiometric reducing agents.
- Bhor, Malhari D.,Bhanushali, Mayur J.,Nandurkar, Nitin S.,Bhanage, Bhalchandra M.
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p. 965 - 969
(2008/09/17)
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- Iron/copper-cocatalyzed ullmann N,O-arylation using FeCl3, CuO, and rac-1,1′-Binaphthyl-2,2′-diol
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We have developed an efficient and inexpensive bimetallic catalyst FeCl3, CuO, and rac-BINOL that could promote N,O-arylation of aliphatic, arylamines, and phenols. The cross-coupling reaction conditions have high tolerance of various functional groups. This versatile and efficient iron/copper-cocatalyst can widely be used in the synthesis of the compounds containing (aryl)C-N or (aryl)C-O(aryl) bond. Georg Thieme Verlag Stuttgart.
- Wang, Zhe,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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body text
p. 2540 - 2546
(2009/04/12)
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- Direct reductive amination of carbonyl compounds using bis(triphenylphosphine) copper(I) tetrahydroborate
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A direct reductive amination protocol for aldehydes/ketones using bis(triphenylphosphine) copper(I) tetrahydroborate as a novel reducing agent in the presence of sulfamic acid has been developed. The reagent chemoselectively reduces the imine moiety and does not affect other reducible functionalities such as chloro, nitro, cyano and methoxy.
- Bhanushali, Mayur J.,Nandurkar, Nitin S.,Bhor, Malhari D.,Bhanage, Bhalchandra M.
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p. 1273 - 1276
(2007/10/03)
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- CuBr/rac-BINOL-catalyzed N-arylations of aliphatic amines at room temperature
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We have developed an efficient and readily available catalyst system CuBr/racemic BINOL ( 1,1′-binaphthyl-2,2′-diol) that catalyzes N-arylation of aliphatic amines at room temperature, and this inexpensive catalyst system is of high selectivity and tolerance toward various functional groups in the substrates.
- Jiang, Deshou,Fu, Hua,Jiang, Yuyang,Zhao, Yufen
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p. 672 - 674
(2007/10/03)
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- The reductive amination of aldehydes and ketones by catalytic use of dibutylchlorotin hydride complex
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The reductive amination of aldehydes or ketones using Ph 2SiH2 or PhSiH3 has been effectively promoted by the direct use of Bu2SnClH-pyridine N-oxide as a catalyst; this method has advantages in terms of its mild conditions and wide application to various carbonyls and amines, including aliphatic examples. The Royal Society of Chemistry 2006.
- Kato, Hirofumi,Shibata, Ikuya,Yasaka, Yuta,Tsunoi, Shinji,Yasuda, Makoto,Baba, Akio
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p. 4189 - 4191
(2007/10/03)
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- Reductive and catalytic monoalkylation of primary amines using nitriles as an alkylating reagent
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(Chemical Equation Presented) A selective and catalytic mono-N-alkylation method of both aromatic and aliphatic amines using nitriles as an alkylating agent with Pd/C or Rh/C as a catalyst is described. This method is particularly attractive to provide an environmentally benign and applicable alkylation method of amines without using toxic and corrosive alkylating agents such as alkyl halides and carbonyl compounds.
- Sajiki, Hironao,Ikawa, Takashi,Hirota, Kosaku
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p. 4977 - 4980
(2007/10/03)
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- Mechanism of acid-catalysed decomposition of 3-alkyl-1,3-diphenyltriazenes by trichloroacetic acid in hexane
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Eight 3-alkyl-1,3-diaryltriazenes with methyl, ethyl, propyl, butyl, pentyl, isopropyl, sec-butyl and cyclohexyl substituents were synthesized and their rate constants of decomposition by trichloroacetic acid (0.01-0.25 mol dm-3) in hexane at 25°C were measured. The kinetic model and mechanism thereof were studied by modelling of the dependences of k obs on the concentration of trichloracetic acid. On the basis of this kinetic model and the interpretation of solvent effects, a reaction mechanism was suggested according to which the triazene reacts with monomer and obviously also opens the dimer of trichloroacetic acid in a single reaction step. At the same time, a non-reactive associate between the N1 nitrogen of triazene and two molecules of trichloroacetic acid is formed in the reaction mixture. The equilibrium and rate constants depend on the addition of trichloroacetic acid as the co-solvent. Copyright
- Pytela, Oldrich,Bednar, Roman,Kavalek, Jaromir
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p. 343 - 349
(2007/10/03)
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