- A novel copper (I) mediated, symmetrical coupling procedure for alkyl, aryl, benzyl, and thiophenyl dihalides
-
A comparative study of Li2CuCl4 vs. Li2CuCl2 mediated mono-coupling reactions of dihalide substrates with allylmagnesium bromide is reported. Higher yields were obtained with Li2CuCl3 and the following trends in halide reactivity were observed. Br > Cl for alkyl, aryl, and thiophenyl dihalides; and benzyl halide > phenyl halide. Utilizing these trends, a symmetrical coupling procedure for alkyl, aryl, benzyl, and thiophenyl dihalides, simply carried out by combining the dihalide with metallic magnesium and Li2CuCl4 is reported.
- Johnson,Johnson, David K.,Ciavarri,Ciavarri, Jeffrey P.,Ishmael,Ishmael, Faoud T.,Schillinger,Schillinger, Kurt J.,Van Geel,Van Geel, Thomas A. P.,Stratton,Stratton, Stephen M.
-
-
Read Online
- MIDA boronate allylation-synthesis of ibuprofen
-
MIDA boronates are among the most useful reagents for the Suzuki-Miyaura reaction. This chemistry typically generates new bonds between two aromatic rings, thereby restricting access to important areas of chemical space. Here we demonstrate the coupling of MIDA boronates to allylic electrophiles, including a new synthesis of the well-known COX inhibitor ibuprofen. This journal is
- Brodie, Glen,France, David J.,Memarzadeh, Sarah,Phillips, David,Tang, Gi Lum
-
p. 30624 - 30630
(2020/09/11)
-
- Manganese catalyzed dehydrogenative silylation of alkenes: Direct access to allylsilanes
-
Dehydrogenative silylation of alkenes with silanes to produce allylsilanes is achieved through manganese catalysis with a wide scope of substrate tolerance. This transformation involves silane radicals initiated by manganese complex without additional oxidant additives. It offers a general, convenient and practical protocol with excellent functional group compatibility and gram-scale capacity for the modular synthesis of allylsilanes.
- Wu, Shang,Zhang, Ying,Jiang, Hongyan,Ding, Ning,Wang, Yanbin,Su, Qiong,Zhang, Hong,Wu, Lan,Yang, Quanlu
-
supporting information
(2020/06/03)
-
- Palladium-Catalyzed Oxidative Allylation of Sulfoxonium Ylides: Regioselective Synthesis of Conjugated Dienones
-
The first examples of palladium-catalyzed allylic C-H oxidative allylation of sulfoxonium ylides to afford the corresponding conjugated dienones with moderate to good yields have been established. The features of this novel conversion include mild reaction conditions, wide substrate scope, and excellent regioselectivity.
- Li, Chunsheng,Li, Meng,Zhong, Wentao,Jin, Yangbin,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
-
supporting information
p. 872 - 875
(2019/05/16)
-
- Palladium-catalyzed tandem isomerization/hydrothiolation of allylarenes
-
Herein we report a tandem olefin migration/hydrothiolation of allyl benzenes facilitated by an in situ generated palladium hydride. A catalyst system composed of palladium acetate and bidentate ligand dtbpx (1,2-bis(di-tert-butylphosphinomethyl)benzene in the presence of catalytic amounts of triflic acid led to the tandem transformation, which furnished benzylic thioethers. The reaction exhibits high regioselectivity and can be conducted under mild conditions. The robustness of the catalyst is displayed through reactions with coordinating thiols.
- Kathe, Prasad M.,Fleischer, Ivana
-
supporting information
p. 2213 - 2217
(2019/03/26)
-
- Palladium-catalyzed allylic C-H oxidation under simple operation and mild conditions
-
We discovered an effective and simple system (Pd/BQ/air/r.t.) for making allylic alcohols through Pd-catalyzed allylic C-H bond functionalization. This approach exhibits advantages due to its simple operation, mild conditions, and environmentally benign features. By modifying reaction conditions, it can be suitable for preparing unsaturated aldehydes, allylic esters, ethers, and amines.
- Guo, Yunlong,Shen, Zengming
-
supporting information
p. 3103 - 3107
(2019/03/26)
-
- Cross-Coupling Reactions of Aryldiazonium Salts with Allylsilanes under Merged Gold/Visible-Light Photoredox Catalysis
-
A method for the cross-coupling reactions of aryldiazonium salts with trialkylallylsilanes via merged gold/photoredox catalysis is described. The reaction is proposed to proceed through a photoredox-promoted generation of an electrophilic arylgold(III) intermediate that undergoes transmetalation with allyltrimethylsilane to form allylarenes.
- Akram, Manjur O.,Mali, Pramod S.,Patil, Nitin T.
-
supporting information
p. 3075 - 3078
(2017/06/23)
-
- Palladium-catalyzed oxidative allylation of bis[(pinacolato)boryl]methane: Synthesis of homoallylic boronic esters
-
A palladium-catalyzed oxidative allylation of bis[(pinacolato)boryl]methane to afford the corresponding homoallylic organoboronic esters with moderate to excellent yields is reported. This novel transformation provides an efficient strategy for the construction of homoallylic organoboronic esters in one step with a broad substrate scope. It is proposed that the palladium-catalyzed oxidative allylic C-H bond activation process may be involved in the catalytic cycle.
- Li, Chunsheng,Li, Meng,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
-
supporting information
p. 66 - 69
(2017/12/27)
-
- Anti-Markovnikov rearrangement in sulfur mediated allylic C-H amination of olefins
-
Cationic rearrangement reactions usually follow Markovnikov's rule to give more substituted carbocations as stable intermediates. During our study on sulfur mediated allylic C-H amination of olefins, very rare cases of anti-Markovnikov rearrangement from secondary carbocations toward primary carbocations or primary triflates were observed.
- Zhang, Zhong,Du, Hongguang,Xu, Jiaxi,Li, Pingfan
-
supporting information
p. 11547 - 11550
(2016/10/03)
-
- Palladium-catalyzed aerobic oxidative double allylic C-H oxygenation of alkenes: A novel and straightforward route to α,β-unsaturated esters
-
A mild tandem oxidative functionalization of allyl aromatic hydrocarbons was accomplished using the catalytic system of Pd(OAc)2/DMA under 1 atm O2. The green twofold C-O bond formation involving double allylic C-H oxygenation unlocks opportunities for markedly different synthetic strategies. Moreover, the reaction affords aryl α,β-unsaturated esters directly from readily available terminal olefins in moderate to good yields with excellent chemo- and stereoselectivities.
- Yang, Wanfei,Chen, Huoji,Li, Jianxiao,Li, Chunsheng,Wu, Wanqing,Jiang, Huanfeng
-
supporting information
p. 9575 - 9578
(2015/06/08)
-
- Screening of by-products of esfenvalerate in aqueous medium using SBSE probe desorption GC-IT-MS technique
-
The pyrethroids, their metabolites and by-products have been recognized as toxic to environment and human health. Despite several studies about esfenvalerate toxicity and its detection in water and sediments, information about its degradation products is still scanty. In this work, esfenvalerate degradation products were obtained by chemical oxidation with hydrogen peroxide and their structure was elucidated using a procedure known as stir bar sorptive extraction (SBSE) probe desorption gas chromatography-ion trap mass spectrometry (GC-IT-MS) analysis. This procedure consists of the thermal desorption of analytes extracted from a SBSE stir bar introduced by a probe into a gas chromatograph (GC) coupled to an ion trap mass spectrometry (IT-MS) system. Based on IT-MS data, a degradation pathway of esfenvalerate is proposed with ten products of chemical oxidation of esfenvalerate that are fully identified. Among these compounds, 3-phenoxybenzoic acid and 3-phenoxybenzaldehyde were detected, reported as being environmental metabolites of some pyrethroids, with endocrine-disrupting activity.
- Colombo, Renata,Ferreira, Tanare C. R.,Yariwake, Janete H.,Lanza, Marcos R. V.
-
p. 1831 - 1837
(2015/09/22)
-
- Direct conversion of allyl arenes to aryl ethylketones via a TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes
-
A TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes was developed. This methodology provides a new efficient and simple route for conversion of a range of allyl arenes directly into aryl ethylketones in good yields with high chemoselectivity.
- Zhao, Jinwu,Liu, Li,Xiang, Shijian,Liu, Qiang,Chen, Huoji
-
supporting information
p. 5613 - 5616
(2015/05/27)
-
- Palladium-catalyzed regioselective azidation of allylic C-H bonds under atmospheric pressure of dioxygen
-
A palladium-catalyzed allylic azidation of alkenes with sodium azide under atmospheric pressure of dioxygen was developed. This methodology provides a new efficient and simple route for accessing allylic azides. Furthermore, the one-pot process consisting of Pd-catalyzed allylic azidation of alkenes and Cu-catalyzed 1,3-dipolar cycloaddition led directly to the 1,2,3-triazole from the alkene. The formed allylic azide can be also in situ reduced to the allylic amine or oxidized to the alkenyl nitrile. the Partner Organisations 2014.
- Chen, Huoji,Yang, Wanfei,Wu, Wanqing,Jiang, Huanfeng
-
supporting information
p. 3340 - 3343
(2014/05/20)
-
- Palladium-catalyzed aerobic oxidative allylic C-H arylation of alkenes with polyfluorobenzenes
-
An aerobic oxidative cross-coupling reaction of alkenes with polyfluorobenzenes, through palladium-catalyzed allylic C-H activation, is reported. This attractive route provides a new way to forge allylic C-C bonds of valuable products, in good yields, with high regioselectivity.
- Jiang, Huanfeng,Yang, Wanfei,Chen, Huoji,Li, Jianxiao,Wu, Wanqing
-
supporting information
p. 7202 - 7204
(2014/07/07)
-
- Isomerizing ethenolysis as an efficient strategy for styrene synthesis
-
A shrinking chain: A bimetallic system consisting of [{Pd(μ-Br)(tBu 3P)}2] and a ruthenium metathesis catalyst has been found to efficiently promote the cross-metathesis between substituted alkenes and ethylene, while continuously migrating the double bond along the alkenyl chain (see scheme). When alkenylarenes, such as the natural products eugenol, safrol, or estragol, were treated with this catalyst under an ethylene atmosphere, they were cleanly converted into the corresponding styrenes and propylene gas. Copyright
- Baader, Sabrina,Ohlmann, Dominik M.,Goossen, Lukas J.
-
supporting information
p. 9807 - 9810
(2013/08/23)
-
- Cyclohexanones by Rh-mediated intramolecular C-H insertion
-
Some long chain α-aryl α-diazo ketones under Rh catalysis cyclize efficiently to the corresponding cyclohexanones. This is in marked contrast to the cyclizations of α-diazo β-ketoesters, which consistently deliver cyclopentanone products.
- Taber, Douglass F.,Paquette, Craig M.,Gu, Peiming,Tian, Weiwei
-
p. 9772 - 9780
(2013/10/22)
-
- Carboxylation of alkylboranes by N-heterocyclic carbene copper catalysts: Synthesis of carboxylic acids from terminal alkenes and carbon dioxide
-
Caught in the act: N-Heterocyclic carbene copper(I) complexes (1; IPr=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) serve as an excellent catalyst for the carboxylation of alkylboranes (2; R=alkyl) with CO2 to afford a variety of functionalized carboxylic acids (3) in high yields. A novel copper methoxide/alkylborane adduct (A) and its subsequent CO2 insertion product (B) have been isolated and shown to be true active catalyst species.
- Ohishi, Takeshi,Zhang, Liang,Nishiura, Masayoshi,Hou, Zhaomin
-
supporting information; experimental part
p. 8114 - 8117
(2011/10/18)
-
- Practical iron-catalyzed allylations of aryl grignard reagents
-
An operationally simple iron-catalyzed reductive cross-coupling reaction between aryl halides and allyl electrophiles has been developed. The underlying domino process exhibits high versatility with respect to the allylic leaving group (acetate, tosylate, diethyl phosphate, methyl carbonate, trimethylsilanolate, methanethiolate, chloride, bromide) and high economic and environmental sustainability with respect to the catalyst system (0.2-5 mol% tris(acetylacetonato)iron(III), ligand-free) and reaction conditions (tetrahydrofuran, 0°C, 45 min).
- Mayer, Matthias,Czaplik, Waldemar M.,Von Wangelin, Axel Jacobi
-
supporting information; experimental part
p. 2147 - 2152
(2010/12/18)
-
- Efficient double bond migration of allylbenzenes catalyzed by Pd(OAc) 2-HFIP system with unique substituent effect
-
A novel catalyst system of Pd(OAc)2-HFIP induces double-bond migration of allylbenzenes under mild conditions with low catalytic loading to afford 1-propenylbenzenes. The reaction shows a unique substituent effect that is highly dependent on the distance of substituents from the allylic moiety. Thus, the reactivity of substrates bearing a methyl group is ordered in para > meta > ortho, whereas it is entirely reversed as ortho > meta > para for methoxy and chloro substituents.
- Nishiwaki, Nagatoshi,Kamimura, Ryuichiro,Shono, Kimihiro,Kawakami, Toshihiko,Nakayama, Katsuhisa,Nishino, Kohei,Nakayama, Takayuki,Takahashi, Keisuke,Nakamura, Aki,Hosokawa, Takahiro
-
supporting information; experimental part
p. 3590 - 3592
(2010/08/19)
-
- Remarkable regioselectivity in microwave-enhanced palladium-catalyzed allylation reaction involving allyltrifluoroborates and aryl halides
-
An unprecedented cross-coupling reaction of potassium allyltrifluoroborates and aryl halides to the corresponding trans-β-methylstyrenes in the presence of PdCl2(dtbpf) catalyst under microwave heating was developed.
- Al-Masum, Mohammad,Alam, Shahrina
-
scheme or table
p. 5201 - 5204
(2009/12/06)
-
- Sodium dithionite initiated addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to allylaromatics. Facile synthesis of conjugated dienes substituted with terminal CF3 group
-
Sodium dithionite effectively promotes the addition of 1-bromo-1-chloro-2,2,2-trifluoroethane to the terminal double bond of allylbenzenes 1. The reactions proceeded in MeCN/H2O to give a 3:1 mole ratio of diastereoisomers of 1-(2-bromo-4-chloro-5,5,5-trifluoropentyl)benzenes 2 as the main products together with small amounts of its reductive debromination products 3. Total yields of 2 and 3 were dependent on the nature of the aromatic ring substituents in 1. Treatment of adducts 2 with DBU in refluxing hexanes resulted in double dehydrohalogenation affording, in good yields, conjugated dienes 4 (1,1,1-trifluoro-5-phenyl-2,4-pentadienes) terminated with the CF3 group at the one end and the phenyl group at the opposite end. These dienes were found to be sufficiently reactive to undergo Diels-Alder condensation with active dienophiles to give trifluoromethylated carbocycles. The reactions of CF3CHClBr with allylheterocycles were less successful and lead to low yields of mixtures of hardly separable compounds or to polymeric resins.
- Ignatowska, Jolanta,Dmowski, Wojciech
-
p. 720 - 729
(2008/03/28)
-
- A highly effective (Triphenyl phosphite)palladium catalyst for a cross-coupling reaction of allylic alcohols with organoboronic acids
-
The cross coupling reaction of aryl and vinyl boronic acids and allylic alcohols proceeded smoothly in toluene or dioxane in the presence of a (triphenyl phosphite)palladium catalyst to give the corresponding allylbenzene derivatives and 1,4-dienes. Neither cocatalysts for promoting C-O bond cleavage of allylic alcohols nor bases for activation of organoboron reagents are required for promoting the coupling process. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Kayaki, Yoshihito,Koda, Takashi,Ikariya, Takao
-
p. 4989 - 4993
(2007/10/03)
-
- Functionalized arylzinc compounds in ethereal solvent: Direct synthesis from aryl iodides and zinc powder and application to Pd-catalyzed reaction with allylic halides
-
Arylzinc compounds, ArZnX, were conveniently prepared in high yields by the reaction of zinc powder with aryl iodides, which contain electron-withdrawing groups such as CO2CH3, CN, Br, or CF3 at the ortho-, meta- or para-position, or electron-donating groups such as CH3, OCH3, or H, at 70 °C in THF, at 100 °C, or at 130 °C in diglyme, respectively. Pd(dba)2 exhibited an outstanding efficient catalytic effect for the cross-coupling of these ethereal solutions of ArZnX with allylic halides to afford a variety of functionalized allylbenzenes in high yields; the reactions were mostly carried out at 0 °C for 5-30 min in the presence of 5 mol % of catalyst. The conversion of the aryl iodides to allylbenzenes via two reactions could be accomplished in one pot.
- Ikegami, Ryo,Koresawa, Akiko,Shibata, Takanori,Takagi, Kentaro
-
p. 2195 - 2199
(2007/10/03)
-
- Tetraalkylammonium salt-based catalyst systems for directing Heck-type reactions. Arylation of allyltrimethylsilane
-
An appropriate selection of the [Pd/base/QX] catalyst systems allows one to direct at will the palladium-catalysed arylation of allyltrimethylsilane towards the formation of either (E)-1-aryl-3-(trimethylsilyl)-1-propene or 3-aryl-1-propene, by preventing
- Jeffery
-
p. 8445 - 8449
(2007/10/03)
-
- Novel coupling reaction of pentaarylantimony with carbon electrophiles
-
The cross-coupling reactions of pentaarylantimony with organic halides and allyl acetate were studied under various conditions of acetonitrile solvent, palladium catalysts and copper iodide. Acetonitrile solvent enabled a nucleophilic coupling reaction with allylic halides, although a radical reaction and an intramolecular ligand coupling have been regarded as general under other conditions. Palladium catalysts were effective for the coupling reaction with allyl acetate. Copper iodide promoted the reaction of organic halides, such as methyl iodide and ethyl bromoacetate. In the latter two cases, the formation of diaryls is a significant side reaction.
- Fujiwara, Masahiro,Tanaka, Mutsuo,Baba, Akio,Ando, Hisanori,Souma, Yoshie
-
-
- Liquid crystals with (polysila) alkyl wing groups
-
A compound of the general formula in which M represents a silicon radical having 2 to 5 silicon atoms which are linked together by bridging elements A, and the remaining valencies of the silicon atoms are saturated with radicals R; A is a bridging element
- -
-
-
- Direct Allylation of Aromatic Compounds with Allylic Chloride using the Supported Reagents System ZnCl2/SiO2-K2CO3/Al2O3
-
Although the reaction of aromatic compounds with allylic chlorides using ZnCl2/SiO2, gives 2-chloro-1-arylalkanes accompanied with diarylalkanes, similar reaction using ZnCl2/SiO2-K2CO3/Al2O3 produces the monoallylated compound as the major product in good yield.
- Kodomari, Mitsuo,Nawa, Satoru,Miyoshi, Tadahiro
-
p. 1895 - 1896
(2007/10/02)
-
- Cyclic Siloxanes with Mesogenic Side Groups
-
Cyclic liquid crystalline siloxanes (CLCS) are optical uniaxial positive (SA, N) and negative (N*) materials in accordance with calamitic structures.X-Ray measurements indicate, that the distances of SA layers correspond with the length of the monomer unit.In the case of mesogens with high polarity the distance is 1.7 fold the length of the monomer unit.A bundle model is proposed for CLC siloxanes.
- Kreuzer, F.-H.,Andrejewski, D.,Haas, W.,Haeberle, N.,Riepl, G.,Spes, P.
-
p. 345 - 378
(2007/10/02)
-
- 1,3-diazolyl-2-phenylalkyl-2-propanol derivatives
-
Heterocyclic compounds of the formula: STR1 wherein X and Y, which may be the same or different, are each a =N-- or =CH-- group and R is a phenyl radical which optionally bears one or more substituents selected from halogen atoms, amino, cyano, carbamoyl,
- -
-
-
- Silicon-directed Elimination from β-Trimethylsilyl Sulphoxides and the Regiospecific Synthesis of Olefins
-
The regiospecific formation of olefins by the thermal elimination of sulphenic acid from β-trimethylsilyl sulphoxides followed by protodesilylation is reported and the effect of the trimethylsilyl group on thermal elimination is discussed.
- Ochiai, Masahito,Tada, Shin-ichi,Sumi, Kenzo,Fujita, Eiichi
-
p. 281 - 282
(2007/10/02)
-
- UMPOLUNG OF REACTIVITY OF ALLYLSILANE, ALLYLGERMANE, AND ALLYLSTANNANE VIA THEIR REACTION WITH THALLIUM (III) SALT: A NEW ALLYLATION REACTION FOR AROMATIC COMPOUND
-
A new direct allylation of the aromatic compound has been developed.A combination of allylsilane, allylgermane, or allylstannane and thallium (III) trifluoroacetate gave rise to an allyl cationic species which was allowed to react with an aromatic compound, a nucleophile, to give allylation product(s) in good yields.
- Ochiai, Masahito,Arimoto, Masao,Fujita, Eiichi
-
p. 4491 - 4494
(2007/10/02)
-