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1.
Gonzalo Blay Dr. Isabel Fernández Dr. M. Carmen Muñoz Prof. Dr. José R. Pedro Prof. Dr. Carlos Vila 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(30):9117-9122
Chiral complexes of BINOL‐based ligands with zirconium tert‐butoxide catalyze the Friedel–Crafts alkylation reaction of indoles with β‐trifluoromethyl‐α,β‐unsaturated ketones to give functionalized indoles with an asymmetric tertiary carbon center attached to a trifluoromethyl group. The reaction can be applied to a large number of substituted α‐trifluoromethyl enones and substituted indoles. The expected products were obtained with good yields and ees of up to 99 %. 相似文献
2.
Vanadium‐Catalyzed Solvent‐Free Synthesis of Quaternary α‐Trifluoromethyl Nitriles by Electrophilic Trifluoromethylation
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Natalja Früh Prof. Dr. Antonio Togni 《Angewandte Chemie (International ed. in English)》2014,53(40):10813-10816
The direct electrophilic trifluoromethylation of silyl ketene imines (SKIs) with hypervalent iodine reagents leads to the formation of quaternary α‐trifluoromethyl nitriles in good yields. This new reaction has been carried out with a variety of substituted SKIs under solvent‐free conditions using a vanadium(IV) catalyst (5 mol %). The corresponding products may be transformed into useful organofluorine building blocks. 相似文献
3.
Asymmetric Conjugate Addition of Benzofuran‐2‐ones to Alkyl 2‐Phthalimidoacrylates: Modeling Structure–Stereoselectivity Relationships with Steric and Electronic Parameters
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Chen Yang En‐Ge Zhang Prof. Xin Li Prof. Jin‐Pei Cheng 《Angewandte Chemie (International ed. in English)》2016,55(22):6506-6510
A highly predictive model to correlate the steric and electronic parameters of tertiary amine thiourea catalysts with the stereoselectivity of Michael reactions of 3‐substituted benzofuranones and alkyl 2‐phthalimidoacrylates is described. As predicted, new 3,5‐bis(trifluoromethyl)benzyl‐ and methyl‐substituted tertiary amine thioureas turned out to be highly suitable catalysts for this reaction and enabled the synthesis of enantioenriched α‐amino acid derivatives with 1,3‐nonadjacent stereogenic centers. 相似文献
4.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(39):12143-12147
A palladium‐catalyzed C(sp3)−C(sp2) Suzuki–Miyaura cross‐coupling of aryl boronic acids and α‐(trifluoromethyl)benzyl tosylates is reported. A readily available, air‐stable palladium catalyst was employed to access a wide range of functionalized 1,1‐diaryl‐2,2,2‐trifluoroethanes. Enantioenriched α‐(trifluoromethyl)benzyl tosylates were found to undergo cross‐coupling to give the corresponding enantioenriched cross‐coupled products with an overall inversion in configuration. The crucial role of the CF3 group in promoting this transformation is demonstrated by comparison with non‐fluorinated derivatives. 相似文献
5.
Asymmetric Diels–Alder Reaction of α‐Substituted and β,β‐Disubstituted α,β‐Enals via Diarylprolinol Silyl Ether for the Construction of All‐Carbon Quaternary Stereocenters
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Prof. Dr. Yujiro Hayashi Dr. Bojan P. Bondzic Tatsuya Yamazaki Yogesh Gupta Shin Ogasawara Prof. Dr. Tohru Taniguchi Prof. Dr. Kenji Monde 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15874-15880
The asymmetric Diels–Alder reaction of α‐substituted acrolein proceeds in the presence of the trifluoroacetic acid salt of trifluoromethyl‐substituted diarylprolinol silyl ether to afford the exo‐isomer with both excellent diastereoselectivity and high enantioselectivity. In the Diels–Alder reaction of a β,β‐disubstituted α,β‐unsaturated aldehyde, good exo‐selectivity and excellent enantioselectivity was obtained when the perchloric acid salt of the bulky triisopropyl silyl ether of trifluoromethyl substituted diarylprolinol was employed as an organocatalyst in the presence of water. In both cases, all‐carbon quaternary stereocenters are constructed enantioselectively. 相似文献
6.
A rhodium(III)‐catalyzed redox‐neutral coupling of α‐trifluoromethylacrylic acid with bezamides proceeds smoothly accompanied by amide‐directed C?H bond cleavage to produce β‐[2‐(aminocarbonyl)phenyl]‐α‐trifluoromethylpropanoic acid derivatives. One of the products can be transformed to a trifluoromethyl substituted heterocyclic compound. In addition, the redox‐neutral coupling of α‐trifluoromethylacrylic acid with related aromatic substrates possessing a nitrogen‐containing directing group can also be conducted under similar conditions. 相似文献
7.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(5):1362-1365
A novel method for the conversion of vinyl triflates into α‐trifluoromethylated ketones in the absence of external trifluoromethyl sources is described. This process accomplishes an efficient migration of the trifluoromethyl group of the triflate to the α‐position in the ketone through a radical process. The reaction proceeds by the addition of a trifluoromethyl radical to the vinyl triflate and subsequent fragmentation of the trifluoromethane sulfonyl radical. Based on this reaction, a one‐pot two‐step procedure for the trifluoromethylation of ketones was developed. The method presented herein also allows the transfer of perfluoroalkyl groups from vinyl perfluoroalkanesulfonates, which are readily accessible from alkynes and perfluoroalkanesulfonic acids. 相似文献
8.
Woo‐Jin Yoo Junpei Kondo Jos A. Rodríguez‐Santamaría Thanh V. Q. Nguyen Sh Kobayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(20):6844-6847
A facile synthetic procedure for the preparation of α‐trifluoromethyl carboxylic acids and esters was achieved through multicomponent coupling reactions between gem‐difluoroalkenes, cesium fluoride, and carbon dioxide. The products were generated in moderate to excellent yields, and the synthetic utility of this method was demonstrated through the preparation of trifluoromethylated versions of popular nonsteroidal anti‐inflammatory drugs (NSAIDs). 相似文献
9.
《Angewandte Chemie (International ed. in English)》2017,56(43):13270-13274
The selective, metal‐free generation of α‐carbonyl cations from simple internal alkynes was accomplished by the addition of a sulfoxide to a densely substituted vinyl cation. The high reactivity of the α‐carbonyl cations was found to efficiently induce hydrogen and even carbon shift reactions with unusual selecivities. Complex compounds with highly congested tertiary and all‐carbon‐substituted quartenary carbon centers can thus be accessed in a single step from simple precursors. Mechanistic analysis strongly supports the intermediacy of the title compounds and provides a simple predictive scheme for the migratory aptitude of different substituents. 相似文献
10.
Heduck Mah Kee Hyuk Chang Kee Dal Nam Hoh‐Gyu Hahn Su Yeoul Bae 《Journal of heterocyclic chemistry》2000,37(4):1003-1008
A new construction of dihydro‐1,4‐dioxin and a synthesis of 5,6‐dihydro‐2‐trifluoromethyl‐1,4‐dioxin‐3‐carboxanilides 22 through polymer‐bound activated ester are described. An intermediate β‐hydroxy ether 18 was prepared from the substitution reaction of α‐thio‐α‐chloro compound 8 with ethylene glycol followed by treatment with Raney Ni. Replacement of hydroxy by chlorine and then dehydrochlorination afforded trifluoromethyl dihydro‐1,4‐dioxin ester 15. The polymer‐bound trifluoromethyl dihydro‐1,4‐dioxin‐3‐carboxylic acid, 4‐hydroxy‐3‐nitrobenzophenone ester ( 21 ) was prepared through the reaction of polystyrene‐bound 4‐hydroxy‐3‐nitrobenzophenone ( 19 ) with the trifluoromethyl dihydro‐1,4‐dioxin‐3‐carbonyl chloride ( 20 ). Refluxing of 21 with substituted aniline in acetonitrile gave the corresponding carboxanilide 22. The reaction rate depended on the nucleophilicity of nitrogen of the aniline. 相似文献
11.
Lewis base could catalyze the formation of a-trifluoromethyl alcohol from CF3SiMe3 and carbonyl-containing compounds. It was found that the α-trifluoromethyl alcohol could also be used to promote the synthesis in basic conditions. 相似文献
12.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(8):2091-2095
The catalytic asymmetric synthesis of both α‐substituted and α,α‐disubstituted (quaternary) β‐tetralones through direct α‐functionalization of the corresponding β‐tetralone precursor remains elusive. A designed Brønsted base‐squaramide bifunctional catalyst promotes the conjugate addition of either unsubstituted or α‐monosubstituted β‐tetralones to nitroalkenes. Under these reaction conditions, not only enolization, and thus functionalization, occurs at the α‐carbon atom of the β‐tetralone exclusively, but adducts including all‐carbon quaternary centers are also formed in highly diastereo‐ and enantioselective manner. 相似文献
13.
Diastereo‐ and Enantioselective Copper(I)‐Catalyzed Intermolecular [3+2] Cycloaddition of Azomethine Ylides with β‐Trifluoromethyl β,β‐Disubstituted Enones
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Zhan‐Ming Zhang Bing Xu Shan Xu Prof. Dr. Hai‐Hong Wu Prof. Dr. Junliang Zhang 《Angewandte Chemie (International ed. in English)》2016,55(21):6324-6328
Reported herein is an asymmetric [3+2] cycloaddition reaction of azomethine ylides with β‐trifluoromethyl β,β‐disubstituted enones, a reaction which is enabled by a Ming‐Phos‐derived copper(I) catalyst (Ming‐Phos=chiral sulfinamide monophosphines, Figure 2 ). This method provides scalable and efficient access to the highly substituted pyrrolidines with a trifluoromethylated, all‐carbon quaternary stereocenter in good yields with up to greater than 20:1 d.r. and 98 % ee. The reaction has a broad substrate scope and tolerates a wide range of functional groups. 相似文献
14.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(47):15269-15273
Described is a facile, scalable route to access functional‐group‐rich gem ‐difluoroalkenes. Using visible‐light‐activated catalysts in conjunction with an arsenal of carbon‐radical precursors, an array of trifluoromethyl‐substituted alkenes undergoes radical defluorinative alkylation. Nonstabilized primary, secondary, and tertiary radicals can be used to install functional groups in a convergent manner, which would otherwise be challenging by two‐electron pathways. The process readily extends to other perfluoroalkyl‐substituted alkenes. In addition, we report the development of an organotrifluoroborate reagent to expedite the synthesis of the requisite trifluoromethyl‐substituted alkene starting materials. 相似文献
15.
Enantioselective Organocatalytic Reduction of β‐Trifluoromethyl Nitroalkenes: An Efficient Strategy for the Synthesis of Chiral β‐Trifluoromethyl Amines
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Elisabetta Massolo Prof. Maurizio Benaglia Manuel Orlandi Dr. Sergio Rossi Giuseppe Celentano 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3589-3595
An efficient organocatalytic stereoselective reduction of β‐trifluoromethyl‐substituted nitroalkenes, mediated by 3,5‐dicarboxylic ester‐dihydropyridines (Hantzsch ester type), has been successfully developed. A multifunctional thiourea‐based (S)‐valine derivative was found to be the catalyst of choice, promoting the reaction in up to 97 % ee. The methodology has been applied to a wide variety of substrates, leading to the formation of differently substituted precursors of enantiomerically enriched β‐trifluoromethyl amines. The mechanism of the reaction and the mode of action of the metal‐free catalytic species were computationally investigated; on the basis of DFT transition‐state (TS) analysis, a model of stereoselection was also proposed. 相似文献
16.
Ring Contraction of 3‐Hydroxy‐3‐(trifluoromethyl)piperidines: Synthesis of 2‐Substituted 2‐(Trifluoromethyl)pyrrolidines
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Alexandra Feraldi‐Xypolia Dr. Domingo Gomez Pardo Prof. Janine Cossy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(37):12876-12880
A ring contraction of 3‐hydroxy‐3‐(trifluoromethyl)piperidines was achieved via an aziridinium intermediate. This contraction facilitates the synthesis of a series of 2‐substituted 2‐(trifluoromethyl)pyrrolidines incorporating a quaternary center at the C2 position. 相似文献
17.
Trifluoromethylation‐Initiated Remote Cross‐Coupling of Carbonyl Compounds to Form Carbon–Heteroatom/Carbon Bonds
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Lin Huang Dr. Sheng‐Cai Zheng Prof. Dr. Bin Tan Prof. Dr. Xin‐Yuan Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6718-6722
By involving the reversal of conventional reactivity expectations without external oxidants, we describe a novel and convenient protocol of remote cross‐coupling of carbonyl compounds with a series of common and simple nucleophiles. This cross‐coupling is triggered by radical trifluoromethylation of alkenes, thereby achieving highly selective remote difunctionalization of alkenes and α‐position of the carbonyl group for facile access to trifluoromethyl α‐halo‐ and α‐cyanocarbonyl compounds. The reaction exhibits a broad substrate scope with excellent functionality tolerance and many different types of nucleophiles; further synthetic applicability of the obtained compounds proved to be suitable, thus showing great potential for synthetic utility. 相似文献
18.
The copper‐catalyzed cross‐coupling reaction of α‐selenoacylzirconocene chloride 3 with haloalkynes in the presence of carbon monoxide gives α‐seleno‐substituted vinyl alkynyl ketones 5 in moderate yields. The reaction conditions are neutral and mild enough (room temperature, 1 atm carbon monoxide) that other functional groups in either coupling partner can be brought unaltered into the coupled product. The E geometry in the α‐alkylseleno vinylzirconocene reagent is maintained during the coupling reaction. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:91–93, 2000 相似文献
19.
《中国化学》2018,36(5):421-429
Reported herein is an example of highly regio‐, diastereo‐ and enantioselective Cu(I)‐catalyzed intermolecular [3+2] cycloaddition reaction of α‐substituted iminoesters with α‐trifluoromethyl α,β‐unsaturated esters. This novel strategy provided a facile access to pyrrolidines with two skipped (aza)quaternary stereocenters including a CF3 all‐carbon quaternary stereocenter. A broad substrate scope was observed and high yields (up to 94%) with excellent diastereoselectivity (up to >20 : 1 d.r.) and enantioselectivity (up to 98% ee) were obtained. 相似文献
20.
Rapid Access to β‐Trifluoromethyl‐Substituted Ketones: Harnessing Inductive Effects in Wacker‐Type Oxidations of Internal Alkenes
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Michael M. Lerch Dr. Bill Morandi Zachary K. Wickens Prof. Dr. Robert H. Grubbs 《Angewandte Chemie (International ed. in English)》2014,53(33):8654-8658
We present a practical trifluoromethyl‐directed Wacker‐type oxidation of internal alkenes that enables rapid access to β‐trifluoromethyl‐substituted ketones. Allylic trifluoromethyl‐substituted alkenes bearing a wide range of functional groups can be oxidized in high yield and regioselectivity. The distance dependence of the regioselectivity was established by systematic variation of the number of methylene units between the double bond and the trifluoromethyl group. The regioselectivity enforced by traditional directing groups could even be reversed by introduction of a competing trifluoromethyl group. Besides being a new powerful synthetic method to prepare fluorinated molecules, this work directly probes the role of inductive effects on nucleopalladation events. 相似文献