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1.
Copper‐Catalyzed Trifluoromethylazidation of Alkynes: Efficient Access to CF3‐Substituted Azirines and Aziridines
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Fei Wang Na Zhu Dr. Pinhong Chen Prof. Dr. Jinxing Ye Prof. Dr. Guosheng Liu 《Angewandte Chemie (International ed. in English)》2015,54(32):9356-9360
A novel method for convenient access to CF3‐containing azirines has been developed, and involves a copper‐catalyzed trifluoromethylazidation of alkynes and a photocatalyzed rearrangement. Both terminal and internal alkynes are compatible with the mild reaction conditions, thus delivering the CF3‐containing azirines in moderate to good yields. The azirines can be converted into various CF3‐substituted aziridines. 相似文献
2.
Xingfeng Bai Caizhi Wu Shaozhong Ge Yixin Lu 《Angewandte Chemie (International ed. in English)》2020,59(7):2764-2768
An asymmetric palladium and copper co‐catalyzed Heck/Sonogashira reaction between o‐iodoacrylanilides and terminal alkynes to synthesize chiral oxindoles was developed. In particular, a wide range of CF3‐substituted o‐iodoacrylanilides reacted with terminal alkynes, affording the corresponding chiral oxindoles containing trifluoromethylated quaternary stereogenic centers in high yields with excellent enantioselectivities (94–98 % ee). This asymmetric Heck/Sonogashira reaction provides a general approach to access oxindole derivatives containing quaternary stereogenic centers including CF3‐substituted ones. 相似文献
3.
Prof. Dr. Valentine G. Nenajdenko Dr. Aleksey A. Goldberg Dr. Vasily M. Muzalevskiy Prof. Dr. Elizabeth S. Balenkova Dr. Aleksey V. Shastin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2370-2383
A convenient and simple three‐step pathway to the new family of CF2CF2S‐bridged alkanes and CF2S‐, CF2O‐bridged alkenes and alkynes was elaborated by using catalytic olefination reaction as a key step of the synthetic sequence. The obtained compounds revealed attractive liquid crystalline characteristics. 相似文献
4.
Sebastian Weske Ramona Schoop Prof. Dr. Konrad Koszinowski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(32):11310-11316
Trifluoromethylation reactions have recently received increased attention because of the beneficial effect of the trifluoromethyl group on the pharmacological properties of numerous substances. A common method to introduce the trifluoromethyl group employs the Ruppert–Prakash reagent, that is, Si(CH3)3CF3, together with a copper(I) halide. We have applied this method to the trifluoromethylation of aromatic alkynes and used electrospray‐ionization mass spectrometry to investigate the mechanism of these reactions in tetrahydrofuran, dichloromethane, and acetonitrile as well as with and without added 1,10‐phenanthroline. In the absence of the alkyne component, the homoleptic ate complexes [Cu(CF3)2]? and [Cu(CF3)4]? were observed. In the presence of the alkynes RH, the heteroleptic complexes [Cu(CF3)3R]? were detected as well. Upon gas‐phase fragmentation, these key intermediates released the cross‐coupling products R?CF3 with perfect selectivity. Apparently, the [Cu(CF3)3R]? complexes did not originate from homoleptic cuprate anions, but from unobservable neutral precursors. The present results moreover point to the involvement of oxygen as the oxidizing agent. 相似文献
5.
Dr. Xingfeng Bai Caizhi Wu Prof. Dr. Shaozhong Ge Prof. Dr. Yixin Lu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(7):2786-2790
An asymmetric palladium and copper co-catalyzed Heck/Sonogashira reaction between o-iodoacrylanilides and terminal alkynes to synthesize chiral oxindoles was developed. In particular, a wide range of CF3-substituted o-iodoacrylanilides reacted with terminal alkynes, affording the corresponding chiral oxindoles containing trifluoromethylated quaternary stereogenic centers in high yields with excellent enantioselectivities (94–98 % ee). This asymmetric Heck/Sonogashira reaction provides a general approach to access oxindole derivatives containing quaternary stereogenic centers including CF3-substituted ones. 相似文献
6.
Palladium‐Catalyzed Cascade CH Trifluoroethylation of Aryl Iodides and Heck Reaction: Efficient Synthesis of ortho‐Trifluoroethylstyrenes
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Hao Zhang Dr. Pinhong Chen Prof. Dr. Guosheng Liu 《Angewandte Chemie (International ed. in English)》2014,53(38):10174-10178
A palladium‐catalyzed selective C? H bond trifluoroethylation of aryl iodides has been explored. The reaction allows for the efficient synthesis of a variety of ortho‐trifluoroethyl‐substituted styrenes. Preliminary mechanistic studies indicate that the reaction might involve a key PdIV intermediate, which is generated through the rate‐determining oxidative addition of CF3CH2I to a palladacycle; the bulky nature of CF3CH2I influences the reactivity. Reductive elimination from the PdIV complex then leads to the formation of the aryl–CH2CF3 bond. 相似文献
7.
Hao Zhang Pinhong Chen Guosheng Liu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(38):10338-10342
A palladium‐catalyzed selective C H bond trifluoroethylation of aryl iodides has been explored. The reaction allows for the efficient synthesis of a variety of ortho‐trifluoroethyl‐substituted styrenes. Preliminary mechanistic studies indicate that the reaction might involve a key PdIV intermediate, which is generated through the rate‐determining oxidative addition of CF3CH2I to a palladacycle; the bulky nature of CF3CH2I influences the reactivity. Reductive elimination from the PdIV complex then leads to the formation of the aryl–CH2CF3 bond. 相似文献
8.
Dr. Tao Xu Dr. Chi Wai Cheung Prof. Dr. Xile Hu 《Angewandte Chemie (International ed. in English)》2014,53(19):4910-4914
Iron catalysis has been developed for the intermolecular 1,2‐addition of perfluoroalkyl iodides to alkynes and alkenes. The catalysis has a wide substrate scope and high functional‐group tolerance. A variety of perfluoroalkyl iodides including CF3I can be employed. The resulting perfluoroalkylated alkyl and alkenyl iodides can be further functionalized by cross‐coupling reactions. This methodology provides a straightforward and streamlined access to perfluoroalkylated organic molecules. 相似文献
9.
Copper‐Catalyzed Difunctionalization of Activated Alkynes by Radical Oxidation–Tandem Cyclization/Dearomatization to Synthesize 3‐Trifluoromethyl Spiro[4.5]trienones
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Dr. Hui‐Liang Hua Yu‐Tao He Yi‐Feng Qiu Ying‐Xiu Li Bo Song Pin Gao Xian‐Rong Song Dong‐Hui Guo Prof. Dr. Xue‐Yuan Liu Prof. Dr. Yong‐Min Liang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(4):1468-1473
A copper‐catalyzed difunctionalizing trifluoromethylation of activated alkynes with the cheap reagent sodium trifluoromethanesulfinate (NaSO2CF3 or Langlois’ reagent) has been developed incorporating a tandem cyclization/dearomatization process. This strategy affords a straightforward route to synthesis of 3‐(trifluoromethyl)‐spiro[4.5]trienones, and presents an example of difunctionalization of alkynes for simultaneous formation of two carbon–carbon single bonds and one carbon–oxygen double bond. 相似文献
10.
Liu XY Guo Z Dong SS Li XH Che CM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(46):12932-12945
An efficient method for the synthesis of tertiary amines through a gold(I)‐catalyzed tandem reaction of alkynes with secondary amines has been developed. In the presence of ethyl Hantzsch ester and [{(tBu)2(o‐biphenyl)P}AuCl]/AgBF4 (2 mol %), a variety of secondary amines bearing electron‐deficient and electron‐rich substituents and a wide range of alkynes, including terminal and internal aryl alkynes, aliphatic alkynes, and electron‐deficient alkynes, underwent a tandem reaction to afford the corresponding tertiary amines in up to 99 % yield. For indolines bearing a preexisting chiral center, their reactions with alkynes in the presence of ethyl Hantzsch ester catalyzed by [{(tBu)2(o‐biphenyl)P}AuCl]/AgBF4 (2 mol %) afforded tertiary amines in excellent yields and with good to excellent diastereoselectivity. All of these organic transformations can be conducted as a one‐pot reaction from simple and readily available starting materials without the need of isolation of air/moisture‐sensitive enamine intermediates, and under mild reaction conditions (mostly room temperature and mild reducing agents). Mechanistic studies by NMR spectroscopy, ESI‐MS, isotope labeling studies, and DFT calculations on this gold(I)‐catalyzed tandem reaction reveal that the first step involving a monomeric cationic gold(I)–alkyne intermediate is more likely than a gold(I)–amine intermediate, a three‐coordinate gold(I) intermediate, or a dinuclear gold(I)–alkyne intermediate. These studies also support the proposed reaction pathway, which involves a gold(I)‐coordinated enamine complex as a key intermediate for the subsequent transfer hydrogenation with a hydride source, and reveal the intrinsic stereospecific nature of these transformations observed in the experiments. 相似文献
11.
1,3‐Dipolar Cycloadditions of Ethyl 2‐Diazo‐3,3,3‐trifluoropropanoate to Alkynes and [1,5] Sigmatropic Rearrangements of the Resulting 3H‐Pyrazoles: Synthesis of Mono‐, Bis‐ and Tris(trifluoromethyl)‐Substituted Pyrazoles
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Daniel Gladow Sebastian Doniz‐Kettenmann Hans‐Ulrich Reissig 《Helvetica chimica acta》2014,97(6):808-821
The 1,3‐dipolar cycloadditions of ethyl 2‐diazo‐3,3,3‐trifluoropropanoate with electron‐rich and electron‐deficient alkynes, as well as the van Alphen? Hüttel rearrangements of the resulting 3H‐pyrazoles were investigated. These reactions led to a series of CF3‐substituted pyrazoles in good overall yields. Phenyl‐ and diphenylacetylene proved to be unreactive, but, at high temperature, the diazoalkane and phenylacetylene furnished a cyclopropene derivative. As expected, the 1,3‐dipolar cycloaddition to the ynamine occurred much faster than those to electron‐deficient alkynes. With one exception, all cycloadditions proceeded with excellent regioselectivities. The [1,5] sigmatropic rearrangement of the primary 3H‐pyrazoles provided products with shifted acyl groups; products resulting from the migration of a CF3 group were not detected. In agreement with literature reports, this rearrangement occurs faster with 3H‐pyrazoles bearing electron‐withdrawing substituents. 相似文献
12.
《Journal of organometallic chemistry》1995,503(2):C51-C54
Donor-free bis(trifluoromethyl)cadmium, (CF3)2Cd, has been obtained at −40 °C from diethylcadmium and CF3I in a quantitative yield. The Raman spectrum of (CF3)2Cd is reported. In the presence of non-coordinating solvents the highly reactive compound eliminates CF2 even below −5°C. Its feasibility as a low temperature difluorocarbene source has been demonstrated by difluorocyclopropenation reactions with some alkenes and alkynes as well as by insertion into metal-chlorine bonds. The NMR spectra of some CF2Cl- and CF3-containing arsanes are reported. 相似文献
13.
Azidoperfluoroalkanes: Synthesis and Application in Copper(I)‐Catalyzed Azide–Alkyne Cycloaddition
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《Angewandte Chemie (International ed. in English)》2017,56(1):346-349
We report an efficient and scalable synthesis of azidotrifluoromethane (CF3N3) and longer perfluorocarbon‐chain analogues (RFN3; RF=C2F5, n C3F7, n C8F17), which enables the direct insertion of CF3 and perfluoroalkyl groups into triazole ring systems. The azidoperfluoroalkanes show good reactivity with terminal alkynes in copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC), giving access to rare and stable N ‐perfluoroalkyl triazoles. Azidoperfluoroalkanes are thermally stable and the efficiency of their preparation should be attractive for discovery programs. 相似文献
14.
Dr. Pavel K. Mykhailiuk 《Angewandte Chemie (International ed. in English)》2015,54(22):6558-6561
A novel approach to agrochemically important difluoromethyl‐substituted pyrazoles has been developed based on the elusive reagent CF2HCHN2, which was synthesized (generated in situ) for the first time and employed in [3+2] cycloaddition reactions with alkynes. The reaction is extremely practical as it is a one‐pot process, does not require a catalyst or the isolation of the potentially toxic and explosive gaseous intermediate, and proceeds in a common solvent, namely chloroform, in air. The reaction is also scalable and allows for the preparation of the target pyrazoles on gram scale. 相似文献
15.
Zhi‐Qi Zhang Meng‐Meng Zheng Xiao‐Song Xue Ilan Marek Fa‐Guang Zhang Jun‐An Ma 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18359-18364
Herein we described an efficient RhII‐catalyzed enantioselective cyclopropenation reaction of internal alkynes with a masked difluorodiazoethane reagent (PhSO2CF2CHN2, Ps‐DFA). This asymmetric transformation offers efficient access to a broad range of enantioenriched difluoromethylated cyclopropenes (40 examples, up to 99 % yield, 97 % ee). The synthetic utility of obtained strained carbocycles is demonstrated by subsequent stereodefined processes, including cross‐couplings, hydrogenation, Diels–Alder reaction, and Pauson–Khand reaction. 相似文献
16.
A protocol that adopts aqueous hydrogen peroxide as a terminal oxidant and [(Me3tacn)(CF3CO2)2RuIII(OH2)]CF3CO2 ( 1 ; Me3tacn=1,4,7‐trimethyl‐1,4,7‐triazacyclononane) as a catalyst for oxidation of alkenes, alkynes, and alcohols to organic acids in over 80 % yield is presented. For the oxidation of cyclohexene to adipic acid, the loading of 1 can be lowered to 0.1 mol %. On the one‐mole scale, the oxidation of cyclohexene, cyclooctene, and 1‐octanol with 1 mol % of 1 produced adipic acid (124 g, 85 % yield), suberic acid (158 g, 91 % yield), and 1‐octanoic acid (129 g, 90 % yield), respectively. The oxidative C?C bond‐cleavage reaction proceeded through the formation of cis‐ and trans‐diol intermediates, which were further oxidized to carboxylic acids via C? C bond cleavage. 相似文献
17.
Ya Li 《Tetrahedron》2009,65(2):478-483
Stereoselective free radical (phenylsulfonyl)difluoromethylation of terminal alkynes with iododifluoromethyl phenyl sulfone (PhSO2CF2I) has been accomplished by using Et3B/air as an initiator. The obtained PhSO2CF2-substituted vinyl iodides, which can be further subjected to Suzuki coupling and Sonogashira coupling reactions, are useful precursors for the preparation of many structurally diverse PhSO2CF2- and CF2H-substituted alkenes. 相似文献
18.
端位炔酮与有机锌试剂CF3CO2ZnEt作用发生自缩合反应,得到较高产率的β取代的Morita-Bayllis-Hillman产物,提供了三取代烯烃化合物的合成方法;而与有机锌试剂CF3CO2ZnCH2I作用时,烷基炔酮不发生反应,只有活性较高的芳基炔酮才能进行反应,得到中等产率的2,5-二氢呋喃衍生物。 相似文献
19.
Spectroscopic Characterization and Crystal Structure of Trifluoromethyl Iodine(III) Chloride Trifluororacetate (CF3I(Cl)OCOCF3) The ternary iodine(III) compound CF3I(Cl)OCOCF3 is obtained by reaction between CF3I(Cl)F and (CH3)3SiOCOCF3 at –50 °C. The molecule was characterized by vibrational spectra, NMR‐spectra, and a crystal structure analysis. CF3I(Cl)OCOCF3 crystallizes monoclinic in the space group P21/c with a = 1102.7(1) pm, b = 785.6(1) pm, c = 989.7(1) pm, and β = 101.34(1)°. 相似文献
20.
Direct Catalytic Trifluoromethylthiolation of Boronic Acids and Alkynes Employing Electrophilic Shelf‐Stable N‐(trifluoromethylthio)phthalimide
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M. Sc. Roman Pluta M. Sc. Pavlo Nikolaienko Prof. Dr. Magnus Rueping 《Angewandte Chemie (International ed. in English)》2014,53(6):1650-1653
A new and safe method for the synthesis of N‐(trifluoromethylthio)phthalimide, a convenient and shelf‐stable reagent for the direct trifluoromethylthiolation, has been developed. N‐(Trifluoromethylthio)phthalimide can be used as an electrophilic source of F3CS+ and reacts readily with boronic acids and alkynes under copper catalysis. The utility of CF3S‐containing molecules as biologically active agents, the mild reaction conditions employed, and the high tolerance of functional groups demonstrate the potential of this new methodology to be widely applied in organic synthesis as well as industrial pharmaceutical and agrochemical research and development. 相似文献