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1.
Filippo Sladojevich Eric McNeill Jonas Brgel Shao‐Liang Zheng Tobias Ritter 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(12):3783-3787
A family of practical, liquid trifluoromethylation and pentafluoroethylation reagents is described. We show how halogen bonding can be used to obtain easily handled liquid reagents from gaseous CF3I and CF3CF2I. The synthetic utility of the new reagents is exemplified by a novel direct arene trifluoromethylation reaction as well as adaptations of other perfluoroalkylation reactions. 相似文献
2.
Dr. Filippo Sladojevich Dr. Eric McNeill Jonas Börgel Dr. Shao‐Liang Zheng Prof. Dr. Tobias Ritter 《Angewandte Chemie (International ed. in English)》2015,54(12):3712-3716
A family of practical, liquid trifluoromethylation and pentafluoroethylation reagents is described. We show how halogen bonding can be used to obtain easily handled liquid reagents from gaseous CF3I and CF3CF2I. The synthetic utility of the new reagents is exemplified by a novel direct arene trifluoromethylation reaction as well as adaptations of other perfluoroalkylation reactions. 相似文献
3.
A Mechanistic Investigation of the Visible‐Light Photocatalytic Trifluoromethylation of Heterocycles Using CF3I in Flow 下载免费PDF全文
Dr. Yuanhai Su Koen P. L. Kuijpers Niels König Minjing Shang Prof. Dr. Volker Hessel Dr. Timothy Noël 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12295-12300
Photocatalytic radical trifluoromethylation strategies have impacted the synthesis of trifluoromethyl‐containing molecules. However, mechanistic aspects concerning such transformations remain poorly understood. Here, we describe in detail the mechanism of the visible‐light photocatalytic trifluoromethylation of N‐methylpyrrole with gaseous CF3I in flow. The use of continuous‐flow microreactor technology allowed for the determination of different important parameters with high precision (e.g., photon flux, quantum yield, reaction rate constants) and for the handling of CF3I in a convenient manner. Our data indicates that the reaction occurs through a reductive quenching mechanism and that there is no radical chain process present. 相似文献
4.
Dr. Kishore Natte Dr. Rajenahally V. Jagadeesh Dr. Lin He Dr. Jabor Rabeah Jianbin Chen Dr. Christoph Taeschler Dr. Stefan Ellinger Dr. Florencio Zaragoza Dr. Helfried Neumann Prof. Dr. Angelika Brückner Prof. Dr. Matthias Beller 《Angewandte Chemie (International ed. in English)》2016,55(8):2782-2786
The CF3 group is an omnipresent motif found in many pharmaceuticals, agrochemicals, catalysts, materials, and industrial chemicals. Despite well‐established trifluoromethylation methodologies, the straightforward and selective introduction of such groups into (hetero)arenes using available and less expensive sources is still a major challenge. In this regard, the selective synthesis of various trifluoromethyl‐substituted (hetero)arenes by palladium‐catalyzed C?H functionalization is herein reported. This novel methodology proceeds under comparably mild reaction conditions with good regio‐ and chemoselectivity. As examples, trifluoromethylations of biologically important molecules, such as melatonin, theophylline, caffeine, and pentoxifylline, are showcased. 相似文献
5.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(5):1395-1399
A fluoroform‐derived borazine CF3− transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C−H and C−X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF3− transfer, and cation modification afforded a reagent with enhanced stability. 相似文献
6.
Jacob B. Geri Michael M. Wade Wolfe Prof. Nathaniel K. Szymczak 《Angewandte Chemie (International ed. in English)》2018,57(5):1381-1385
A fluoroform‐derived borazine CF3? transfer reagent is used to effect rapid nucleophilic reactions in the absence of additives, within minutes at 25 °C. Inorganic electrophiles spanning seven groups of the periodic table can be trifluoromethylated in high yield, including transition metals used for catalytic trifluoromethylation. Organic electrophiles included (hetero)arenes, enabling C?H and C?X trifluoromethylation reactions. Mechanistic analysis supports a dissociative mechanism for CF3? transfer, and cation modification afforded a reagent with enhanced stability. 相似文献
7.
Yilin Zhao Tingting Hou Liming Zhang Xue Wang Jingli Hou Yangping Liu Guifang Han Yuguang Song 《European journal of organic chemistry》2023,26(18):e202300253
An iron-catalyzed trifluoromethylation of indole-tethered alkene with Togni's reagent to construct CF3-containing spiro[indole-3,3′-pyrrolidine] and tetrahydrocarbazole derivatives under mild and convenient conditions has been disclosed. Mechanistic studies indicate that the reaction proceed through a CF3 radical addition to the alkene, followed by sequential dearomatizing spiocyclization of the indole and oxidation to afford the spiro[indole-3,3′-pyrrolidine] derivatives. Meanwhile, when the substituent at the C2 position of the indole is hydrogen, the CF3-containing tetrahydrocarbazole is obtained through trifluoromethylation of alkene and cyclization of indole. 相似文献
8.
Copper‐Catalyzed Highly Stereoselective Trifluoromethylation and Difluoroalkylation of Secondary Propargyl Sulfonates 下载免费PDF全文
Xing Gao Yu‐Lan Xiao Xiaolong Wan Prof. Dr. Xingang Zhang 《Angewandte Chemie (International ed. in English)》2018,57(12):3187-3191
It is challenging to stereoselectively introduce a trifluoromethyl group (CF3) into organic molecules. To date, only limited strategies involving direct asymmetric trifluoromethylation have been reported. Herein, we describe a new strategy for direct asymmetric trifluoromethylation through the copper‐catalyzed stereospecific trifluoromethylation of optically active secondary propargyl sulfonates. The reaction enables propargylic trifluoromethylation with high regioselectivity and stereoselectivity. The reaction could also be extended to stereospecific propargylic difluoroalkylation. Transformations of the resulting enantiomerically enriched fluoroalkylated alkynes led to a variety of chiral fluoroalkylated compounds, thus providing a useful protocol for applications in the synthesis of fluorinated complexes. 相似文献
9.
N. A. Samokhvalova P. A. Khavrel’ A. A. Goryunkov I. N. Ioffe V. L. Karnatsevich L. N. Sidorov E. Kemnitz S. I. Troyanova 《Russian Chemical Bulletin》2008,57(12):2526-2534
HPLC separation of the products of high-temperature reaction of a sublimed mixture of C60–C70 (10: 1) with CF3I in a sealed ampoule allowed isolation and determination of molecular structures (X-ray crystallography and 19F NMR) of two new isomers of C60(CF3)12 and one isomer of C60(CF3)14. These isomers are characterized by low relative formation energies, which suggests that the trifluoromethylation process is basically under the thermodynamic control. 相似文献
10.
A silver‐mediated oxidative trifluoromethylation of easily accessible α‐trifluoromethyl alcohols with TMSCF3 was developed to access novel CF3(OCF3)CH‐containing compounds. Deprotonation of CF3(OCF3)CH‐substituted arenes afforded synthetically useful CF3O‐substituted gem‐difluoroalkenes. Furthermore, evaluation of the lipophilicities (log P) indicated that CH(OCF3)CF3 is more lipophilic than the common fluorinated motifs such as CF3, OCF3, and SCF3, thus rendering the CH(OCF3)CF3 motif appealing in drug discovery. 相似文献
11.
Rhodium‐Catalyzed Geminal Oxyfluorination and Oxytrifluoro‐Methylation of Diazocarbonyl Compounds 下载免费PDF全文
Dr. Weiming Yuan Dr. Lars Eriksson Prof. Kálmán J. Szabó 《Angewandte Chemie (International ed. in English)》2016,55(29):8410-8415
A new reaction for the rhodium‐catalyzed geminal‐difunctionalization‐based fluorination is presented. The substrates are aromatic and aliphatic diazocarbonyl compounds. As the fluorine source a stable and easily accessible benziodoxole reagent was used. A variety of alcohol, phenol, and carboxylic acid reagents were employed to introduce the second functionality. The reaction was extended to trifluoromethylation using a benziodoxolon reagent. The fluorination and trifluoromethylation reactions probably proceed by a rhodium‐containing onium ylide type intermediate, which is trapped by either the F or CF3 electrophiles. 相似文献
12.
Trifluoromethanesulfonic Anhydride as a Low‐Cost and Versatile Trifluoromethylation Reagent 下载免费PDF全文
Yao Ouyang Dr. Xiu‐Hua Xu Prof. Dr. Feng‐Ling Qing 《Angewandte Chemie (International ed. in English)》2018,57(23):6926-6929
A large number of reagents have been developed for the synthesis of trifluoromethylated compounds. However, an ongoing challenge in trifluoromethylation reaction is the use of less expensive and practical trifluoromethyl sources. We report herein the unprecedented direct trifluoromethylation of (hetero)arenes using trifluoromethanesulfonic anhydride as a radical trifluoromethylation reagent by merging photoredox catalysis and pyridine activation. Furthermore, introduction of both the CF3 and OTf groups of the trifluoromethanesulfonic anhydride into internal alkynes to access tetrasubstituted trifluoromethylated alkenes was achieved. Since trifluoromethanesulfonic anhydride is a low‐cost and abundant chemical, this method provides a cost‐efficient and practical route to trifluoromethylated compounds. 相似文献
13.
Visible‐Light‐Induced Trifluoromethylation of Isonitrile‐Substituted Methylenecyclopropanes: Facile Access to 6‐(Trifluoromethyl)‐7,8‐Dihydrobenzo[k]phenanthridine Derivatives 下载免费PDF全文
Yu‐Chao Yuan Hou‐Lu Liu Xu‐Bo Hu Prof. Dr. Yin Wei Prof. Dr. Min Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13059-13063
A new visible‐light‐induced trifluoromethylation of isonitrile‐substituted methylenecyclopropanes is developed. A range of substituted 6‐(trifluoromethyl)‐7,8‐dihydrobenzo[k]phenanthridine derivatives are readily furnished by this newly developed tandem reaction with moderate to good yields. This reaction allows the direct formation of two six‐membered rings and three new C?C bonds, including the C?CF3 bond, under visible light irradiation. 相似文献
14.
We report herein the direct N‐trifluoromethylation of N‐H amides. Promoted by AgOTf and 2‐fluoropyridine, the reaction of a variety of amides with Selectfluor, TMSCF3 and CsF proceeds smoothly at room temperature leading to the corresponding N‐trifluoromethylated products in satisfactory yields. The protocol is also applicable to amino acid derivatives, resulting in efficient and chemoselective N‐trifluoromethylation of di‐ and tri‐peptides with retention of configuration. A mechanism involving reductive elimination of Ag(III) intermediates to form N—CF3 bonds is proposed. 相似文献
15.
A new electrochemical strategy for trifluoromethylation/cyclization using TfNHNHBoc as a CF3 source was established. This approach was realized by the direct electrolysis of Tf NHNHBoc under external oxidantfree and catalyst-free conditions, and afforded various trifluoromethylated oxindoles with good functional group compatibility and broad substrate scope. Preliminary mechanistic studies show that the reaction proceeds by a radical process. 相似文献
16.
Nadezhda B. Tamm Runnan Guan Shangfeng Yang Erhard Kemnitz Sergey I. Troyanov 《化学:亚洲杂志》2019,14(12):2108-2111
High‐temperature trifluoromethylation of isolated‐pentagon‐rule (IPR) fullerene C92 chlorination products followed by HPLC separation of C92(CF3)n derivatives resulted in the isolation and X‐ray structural characterization of IPR C92(38)(CF3)18 and non‐classical C92(NC)(CF3)22. The formation of C92(38)(CF3)18 as the highest CF3 derivative of the known isomer C92(38) can be expected. The formation of C92(NC)(CF3)22 was interpreted as chlorination‐promoted cage transformation of C92(38) followed by trifluoromethylation of non‐classical C92(NC) chloride. Noticeably, C92(NC)(CF3)22 shows the highest degree of trifluoromethylation among all known CF3 derivatives of fullerenes. The addition patterns of C92(38)(CF3)18 and C92(NC)(CF3)22 are discussed and compared to the chlorination patterns of C92(38)Cln compounds. 相似文献
17.
Synthesis,Isolation and Structure of Trifluoromethylated Fullerene D3‐C78, C78(1)(CF3)10−18 下载免费PDF全文
Maria P. Kosaya Dr. Maria A. Fritz Victor A. Brotsman Dr. Nadezhda B. Tamm Dr. Daria V. Ignat'eva Prof. Dr. Sergey I. Troyanov 《化学:亚洲杂志》2016,11(7):1000-1003
High‐temperature trifluoromethylation of fullerene C78 followed by HPLC separation of C78(CF3)n derivatives resulted in the isolation and X‐ray structural characterization of 15 compounds, that is, two C78(1)(CF3)10, three C78(1)(CF3)12, four C78(1)(CF3)14, and five C78(1)(CF3)16 isomers as well as one isomer of C78(1)(CF3)18. The addition patterns of the C78(1)(CF3)n molecules are discussed in terms of trifluoromethylation pathways and relative formation energies. 相似文献
18.
In situ monitoring of the trifluoromethylation of caffeine using Zn(SO2CF3)2 provides mechanistic insight into this important reaction. The concentration dependences of each of the reagents are probed, along with the effect of various additives. The kinetic profile is characterized by a rapid initial regime followed by a period of slower rate. Increasing the concentration of the Zn reagent extends the initial rapid period to higher conversions. Neither the caffeine concentration nor the concentration of the oxidant has a strong effect on the reaction rate. A multiple aliquot method is introduced to help deconvolute factors associated with each rate regime. 相似文献
19.
Copper‐Catalyzed Trifluoromethylation of Internal Olefinic CH Bonds: Efficient Routes to Trifluoromethylated Tetrasubstituted Olefins and N‐Heterocycles 下载免费PDF全文
Zhifeng Mao Fei Huang Dr. Haifeng Yu Prof. Dr. Jiping Chen Prof. Dr. Zhengkun Yu Prof. Dr. Zhaoqing Xu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(12):3439-3445
The functionalization of internal olefins has been a challenging task in organic synthesis. Efficient CuII‐catalyzed trifluoromethylation of internal olefins, that is, α‐oxoketene dithioacetals, has been achieved by using Cu(OH)2 as a catalyst and TMSCF3 as a trifluoromethylating reagent. The push–pull effect from the polarized olefin substrates facilitates the internal olefinic C?H trifluoromethylation. Cyclic and acyclic dithioalkyl α‐oxoketene acetals were used as the substrates and various substituents were tolerated. The internal olefinic C?H bond cleavage was not involved in the rate‐determining step, and a mechanism that involves radicals is proposed based on a TEMPO‐quenching experiment of the trifluoromethylation reaction. Further derivatization of the resultant CF3 olefins led to multifunctionalized tetrasubstituted CF3 olefins and trifluoromethylated N‐heterocycles. 相似文献
20.
Jian‐Bo Liu Chao Chen Lingling Chu Zeng‐Hao Chen Xiu‐Hua Xu Feng‐Ling Qing 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(40):12005-12008
Aryl trifluoromethyl ethers (ArOCF3) are prevalent in pharmaceuticals, agrochemicals, and materials. However, methods for the general and efficient synthesis of these compounds are extremely underdeveloped and limited. Herein, we describe a highly efficient and general procedure for the direct O‐trifluoromethylation of unprotected phenols through a silver‐mediated cross‐coupling reaction using CF3SiMe3 as the CF3 source and exogenous oxidants. This novel oxidative trifluoromethylation provides access to a wide range of aryl trifluoromethyl ethers from simple phenols. The mild process was also applied to the late‐stage trifluoromethylation of a medicinally relevant compound. 相似文献