共查询到20条相似文献,搜索用时 46 毫秒
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Rajrani Narvariya Dr. Suman Das Susmita Mandal Dr. Archana Jain Prof. Tarun K. Panda 《欧洲无机化学杂志》2023,26(25):e202300247
We report catalytic hydroboration of esters as well as nitriles under solvent-free and mild conditions using single titanium(IV) metal complex, [{κ2-C6H4C(O)N(iPr)C(N-iPr)=N}{κ3-(iPr)N=C(O)−C6H4−NC(NMe2)N(iPr)}TiNMe2] 1 as a sustainable, economical, and efficient pre-catalyst. The molecular structure of the TiIV complex in the solid state reveals the unique coordination of TiIV metal with N, N, and O atoms of one quinazolinone unit via in-situ rearrangement, while another quinazolinone moiety coordinates in bidentate fashion via both N atoms only. The TiIV complex demonstrates excellent activity as a pre-catalyst towards the hydroboration of a wide array of esters and nitriles with pinacolborane (HBpin) to afford alkoxyboranes and diboryl amines in high yield (up to 99 %) with greater tolerance to a variety of electron-withdrawing and electron-donating functional groups. A most plausible mechanism of hydroboration of esters is also proposed based on kinetics and NMR studies, which suggests the formation of titanium-hydride species as an active catalyst. 相似文献
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A variety of aldehyde N,N-dimethylhydrazones are rapidly converted into the corresponding nitriles using oxone supported on wet Al2O3 under microwave irradiation in dry media. 相似文献
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In order to establish a rapid conversion method of primary amides to nitriles, various types of carboxamides were treated with 2,2,2-trichloroethyl chloroformate and Et3N, as a dehydrating agent to obtain the desired nitriles in 82–95% yields. 相似文献
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Krishnappa Manjula 《合成通讯》2013,43(9):1545-1550
A rapid and facile method for the conversion of primary amides to nitriles using inexpensive and readily available ZnCl2 in aqueous acetonitrile and their regeneration using ZnCl2–H2O–THF in the presence of acetamide under microwave irradiation in good yields is reported. The reactions go to completion within a minute. 相似文献
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A. Hess H. C. Guelen N. Alandini A. Mourati Y. C. Guersoy Prof. P. Knochel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(1):e202103700
A selective ortho,ortho’-functionalization of readily available aryl oxazolines by two successive magnesiations with sBu2Mg in toluene followed by trapping reactions with electrophiles, such as (hetero)aryl iodides or bromides, iodine, tosyl cyanide, ethyl cyanoformate or allylic bromides (39 examples, 62–99 % yield) is reported. Treatment of these aryl oxazolines with excess oxalyl chloride and catalytic amounts of DMF (50 °C, 4 h) provided the corresponding nitriles (36 examples, 73–99 % yield). Conversions of these nitriles to valuable heterocycles are reported, and a tentative mechanism is proposed. 相似文献
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Dr. Jinho Kim Hyun Jin Kim Prof. Sukbok Chang 《Angewandte Chemie (International ed. in English)》2012,51(48):11948-11959
Aromatic nitriles are prepared efficiently through transition‐metal‐mediated cyanation of aryl (pseudo)halides with metallic cyano‐group sources, such as CuCN, KCN, NaCN, Zn(CN)2, TMSCN, or K4[Fe(CN)6]. However, this approach often suffers from drawbacks, such as the formation of stoichiometric amounts of metal waste, the poisoning of the metal catalysts, or the generation of toxic HCN gas. As a result, a range of “nonmetallic” organic cyano‐group sources have been explored for the cyanation of aryl halides and arene C? H bonds. This Minireview summarizes types of nonmetallic cyano‐group sources and their applications in the preparation of aryl nitriles. 相似文献
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Ruthenium-Catalyzed Deaminative Hydrogenation of Amino Nitriles: Direct Access to 1,2-Amino Alcohols
Dr. Pilar Calleja Dr. Martin Ernst Prof. Dr. A. Stephen K. Hashmi Dr. Thomas Schaub 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(40):9498-9503
A new approach for the efficient and highly selective synthesis of 1,2-amino alcohols by direct reductive hydrolysis of N-formyl-protected α-amino nitriles is reported. The commercially available RuHCl(CO)(PPh3)3 complex was found to be a suitable catalyst for this operationally simple protocol, in which no stoichiometric amounts of undesired metal waste are generated. The deaminative hydrogenation is performed at 55 bar of H2, using a 6:1 mixture of 1,4-dioxane/water as solvent. In addition, hydroxymethyl alcohols were prepared from cyanoketones under very similar conditions. 相似文献
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Sabrina Ouizem Dr. Sandrine Cheramy Dr. Candice Botuha Prof. Fabrice Chemla Dr. Franck Ferreira Dr. Alejandro Pérez‐Luna 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12668-12677
Stereoselective cyclization of zincated α‐N‐homoallylamino nitriles has been developed. Following treatment with lithium diisopropylamide (LDA) and transmetalation with zinc bromide, α‐N‐(1‐phenylethyl)‐N‐homoallylamino nitriles lead to 2,3‐methanopyrrolidines in moderate to good yields (up to 66 %) and excellent selectivities (up to >98:2). With substrates derived from α‐branched homoallylic amines, a stereospecific inversion of the homoallylic stereogenic center was observed. To account for this, a mechanistic rationale involving the formation of zincioiminium ions from zincated α‐amino nitriles is put forward. 2,3‐Methanopyrrolidines should then arise from a sequence involving an aza‐Cope rearrangement providing a configurationally stable (2‐azoniaallyl)zinc species that then undergoes a [3+2] cycloaddition reaction. 相似文献
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I. Iovel L. Golomba J. Popelis A. Gaukhman E. Lukevics 《Chemistry of Heterocyclic Compounds》2003,39(6):721-725
The addition of trimethylsilyl cyanide to the CH=N bond of furan, thiophene, and pyridine azomethines in the presence of aluminum bromide as catalyst was studied. The effect of the CF3 group in the aldimines produced by the condensation of O-, S-, and N-heteroaromatic aldehydes with 2-trifluoromethylaniline on the reaction and also other relationships of the investigated processes were studied. The corresponding furan, thiophene, and pyridine -amino nitriles were synthesized. 相似文献
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Dipl.‐Chem. Lisanne Becker Dr. Perdita Arndt Dr. Anke Spannenberg Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(39):12595-12600
The reactions of the Group 4 metallocene alkyne complexes rac‐(ebthi)M(η2‐Me3SiC2SiMe3) ( 1 a : M=Ti, 1 b : M=Zr; rac‐(ebthi)=rac‐1,2‐ethylene‐1,1′‐bis(η5‐tetrahydroindenyl)) with Ph?C?N were investigated. For 1 a , an unusual nitrile–nitrile coupling to 1‐titana‐2,5‐diazacyclopenta‐2,4‐diene ( 2 ) at ambient temperature was observed. At higher temperature, the C?C coupling of two nitriles resulted in the formation of a dinuclear complex with a four‐membered diimine bridge ( 3 ). The reaction of 1 b with Ph?C?N afforded dinuclear compound 4 and 2,4,6‐triphenyltriazine. Additionally, the reactivity of 1 b towards other nitriles was investigated. 相似文献
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SmI2 has been found to catalyze a reaction of cyclotrimerization of nitriles in the presence of amine as cocatalyst to give 2,4,6-trisubstituted-s-triazines effectively under mild reaction conditions. The yield depends on the structure of nitriles. 相似文献
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Aromatic, alicyclic, olefinic as well as heterocyclic aldoximes, were dehydrated to their corresponding nitriles with 0.15 molar equivalents of TiCl3(OTf) in sealed tube at 80°C in 85-97% yield. 相似文献
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Gernot Boche 《Angewandte Chemie (International ed. in English)》1989,28(3):277-297
Acceptor-substituted lithio compounds LiA? CR1R2, in which the acceptor A is an RC(0), N?C, RSO2, RS(O)NR, RSO, RS, O2N, or RC(N? NR2) group, have long played an important role in organic synthesis. Their significance has grown still further in the last fifteen years, as one has increasingly learnt to employ them successfully in chemo-, regio-, diastereo-and enantioselective reactions. Remarkably, little if anything was known of the structures of these compounds. It is therefore not surprising that interest in the structures of this class of compounds has greatly increased in recent years. In the following review, we shall summarize recent research into the structures of the lithio compounds of sulfones, sulfoximides, sulfoxides, thioethers and 1,3-dithianes, nitriles, nitro compounds, and hydrazones. Crystal structure determinations from recent years are central to this study. They are supplemented by solution studies and by calculations of structures. Structural similarities and differences between the individual states of aggregation are pointed out wherever possible, as is also the relationship between structure and reactivity. 相似文献
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Maniklal Shee Sk. Sheriff Shah Prof. N. D. Pradeep Singh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(62):14070-14074
This report presents the visible-light-assisted synthesis of aryl nitriles from easily accessible alcohols or methyl arenes in the presence of O2. Organic photoredox catalyst, 4CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene), induces single electron transfer (SET) from azide N3− and generates azide radical N3⋅.The photogenerated N3⋅ abstracts H atom from α-C−H bond of benzylic system, which provides aldehyde and hydrazoic acid (HN3) in situ. This reaction subsequently forms azido alcohol intermediate that transforms into nitrile with the assistance of triflic acid (Brønsted acid). A range of alcohols and methyl arenes successfully underwent cyanation at room temperature with good to excellent yields and showed good functional group tolerance. 相似文献
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The Addition of Nitriles to Tetramesityldisilene: A Comparison of the Reactivity between Surface and Molecular Disilenes 下载免费PDF全文
Dr. Julie A. Hardwick Prof. Kim M. Baines 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2480-2488
The addition of acetonitrile, propionitrile, and phenylacetonitrile to tetramesityldisilene (Mes2Si?SiMes2) was examined. In general, 1,2,3‐azadisiletines and the tautomeric enamines were formed, although a ketenimine was formed as the major product in the addition of phenylacetonitrile to the disilene. In the presence of LiCl, the mode of addition changed for both acetonitrile and propionitrile: insertion into the α‐CH bond of acetonitrile and/or formation of the formal HCN adduct was observed. Preliminary investigations of the reactivity of the nitrile adducts are also reported. A comparison between the reactivity of nitriles with Mes2Si?SiMes2 and the Si(100)‐2×1 surface was made both in terms of the types of adducts formed and their reactivity. Some insights into the surface chemistry are offered. 相似文献
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M. L. Kuznetsov L. V. Kozlova A. I. Dement’ev 《Russian Journal of Inorganic Chemistry》2006,51(10):1602-1612
The mechanism of 1.3-dipolar cycloaddition of nitrones (CH2=N(CH3)O) to doubly activated nitriles RCN has been comprehensively studied by theoretical quantum-chemical methods for the model compound trans-[PtCl2(N≡CCH3)(N≡CCF3)] as an example. The reaction proceeds by a strongly asynchronous concerted mechanism through the formation of a five-membered cyclic transition state. Studying the effect of a solvent on the process shows that solvation effects inhibit cycloaddition. Double activation of RCN by introducing the electron-withdrawing substituents R = CF3 followed by coordination to a transition metal is the most promising way to enhance the reactivity of nitriles in cycloaddition reactions. 相似文献
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Cyclic cyano derivatives 3 were obtained by the reaction of Me3SiCN / ZnI2 with the cyclic ketones 2 which gave the trimethylsilyloxy nitriles 4. They were directly transformed to cyano derivatives 3 (70–80% yield) by the reductive reagent Me3SiCl-NaI in acetonitrile in the presence of H2O. 相似文献
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Strecker reactions of various aldimines as well as ketoimines with TMSCN proceeded smoothly under mild conditions to give the corresponding α-amino nitriles and α,α-disubstituted α-amino nitriles, respectively, in good to excellent yields in the presence of nanocrystalline magnesium oxide. The reaction proceeds through hypervalent silicate species by coordination to O2−/O− (Lewis basic site) of nanocrystalline magnesium oxide, proved by 29Si NMR. 相似文献
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Asymmetric Hydrogenation of α,β‐Unsaturated Nitriles with Base‐Activated Iridium N,P Ligand Complexes 下载免费PDF全文
Marc‐André Müller Prof. Dr. Andreas Pfaltz 《Angewandte Chemie (International ed. in English)》2014,53(33):8668-8671
Although many chiral catalysts are known that allow highly enantioselective hydrogenation of a wide range of olefins, no suitable catalysts for the asymmetric hydrogenation of α,β‐unsaturated nitriles have been reported so far. We have found that Ir N,P ligand complexes, which under normal conditions do not show any reactivity towards α,β‐unsaturated nitriles, become highly active catalysts upon addition of N,N‐diisopropylethylamine. The base‐activated catalysts enable conjugate reduction of α,β‐unsaturated nitriles with H2 at low catalyst loadings, affording the corresponding saturated nitriles with high conversion and excellent enantioselectivity. In contrast, alkenes lacking a conjugated cyano group do not react under these conditions, making it possible to selectively reduce the conjugated C?C bond of an α,β‐unsaturated nitrile, while leaving other types of C?C bonds in the molecule intact. 相似文献