- Aryl Diazonium Salts: Powerful Arylating Agents for Catellani-Typeortho-Arylation
-
The Catellani reaction provides an efficient synthetic approach to polyfunctionalized arenes. However, the selectiveortho-arylating reagents employed in these reactions have been strictly limited to activated bromoarenes. As demonstrated in this work, aryl diazonium salts bearing both electron-donating and electron-withdrawing substituents, after in situ transformations with KI into the corresponding iodoarenes, were efficient arylating reagents for Catellani typeortho-arylation approaches.
- Fu, Ying,Guo, Liang-Liang,Zhang, Yu-Xia
-
supporting information
p. 17437 - 17444
(2021/12/02)
-
- Heterogeneous visible-light-induced Meerwein hydration reaction of alkenes in water using mpg-C3N4 as a recyclable photocatalyst
-
A green and efficient visible light induced Meerwein hydration reaction of alkenes in aqueous medium using mpg-C3N4 as a recyclabe photocatalyst has been disclosed. This protocol provides a direct approach for the preparation of racemic alcohols via a free radical mechanism. Water acted as both a solvent and a reagent without any additives or co-solvents. The metal-free heterogeneous semiconductor is found to be fully recyclable at least 5 times without any significant reduction in activity. The Meerwein hydration reaction has an excellent substrate scope and gave the desired products in moderate to high yields. Furthermore, this reaction could be carried out under solar light irradiation and is applicable for large-scale reactions with satisfactory results.
- Wang, Jingjing,Xue, Linshuang,Hong, Mei,Ni, Bangqing,Niu, Tengfei
-
supporting information
p. 411 - 416
(2020/02/13)
-
- Modular and Selective Arylation of Aryl Germanes (C?GeEt3) over C?Bpin, C?SiR3 and Halogens Enabled by Light-Activated Gold Catalysis
-
Selective C (Formula presented.) –C (Formula presented.) couplings are powerful strategies for the rapid and programmable construction of bi- or multiaryls. To this end, the next frontier of synthetic modularity will likely arise from harnessing the coupling space that is orthogonal to the powerful Pd-catalyzed coupling regime. This report details the realization of this concept and presents the fully selective arylation of aryl germanes (which are inert under Pd0/PdII catalysis) in the presence of the valuable functionalities C?BPin, C?SiMe3, C?I, C?Br, C?Cl, which in turn offer versatile opportunities for diversification. The protocol makes use of visible light activation combined with gold catalysis, which facilitates the selective coupling of C?Ge with aryl diazonium salts. Contrary to previous light-/gold-catalyzed couplings of Ar–N2+, which were specialized in Ar–N2+ scope, we present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. Our computational data suggest that while electron-poor Ar–N2+ salts are readily activated by gold under blue-light irradiation, there is a competing dissociative deactivation pathway for excited electron-rich Ar–N2+, which requires an alternative photo-redox approach to enable productive couplings.
- Dahiya, Amit,Fricke, Christoph,Funes-Ardoiz, Ignacio,Gevondian, Avetik G.,Schoenebeck, Franziska,Sherborne, Grant J.
-
supporting information
p. 15543 - 15548
(2020/06/22)
-
- Copper-mediated tandem ring-opening/cyclization reactions of cyclopropanols with aryldiazonium salts: Synthesis of: N -arylpyrazoles
-
A general method for the synthesis of structurally diverse N-arylpyrazoles from readily available cyclopropanols and aryldiazonium salts is disclosed. The reaction was conducted at room temperature within minutes with a broad substrate scope and excellent regioselectivity.
- Liu, Jidan,Xu, Erjie,Jiang, Jinyuan,Huang, Zeng,Zheng, Liyao,Liu, Zhao-Qing
-
supporting information
p. 2202 - 2205
(2020/02/26)
-
- Pentafluoroethylation of Arenediazonium Tetrafluoroborates Using On-Site Generated Tetrafluoroethylene
-
Copper-mediated pentafluoroethylation of arenediazonium tetrafluoroborates with tetrafluoroethylene (TFE) on-site generated from TMSCF3 has been developed as a new method to prepare pentafluoroethyl arenes. The active pentafluoroethylation reagent “CuC2F5” is pre-generated from CuSCN, TFE and CsF, and its generation and further reaction are strongly solvent-dependent. This pentafluoroethylation reaction represents the first example of Sandmeyer-type pentafluoroethylation, which exhibits good functional group tolerance and potential applications for the synthesis of complicated bioactive compounds.
- Xing, Bo,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
-
supporting information
p. 1131 - 1136
(2019/10/22)
-
- Copper(I)-promoted trifluoromethylthiolation of arenediazonium salts with AgSCF3
-
An efficient method for trifluoromethylthiolation of arenediazonium salts has been developed in mild conditions with a stable and convenient AgSCF3. It provides a straightforward and convenient way for the synthesis of trifluoromethylthiolated compound from diazonium salts in moderate to good yields.
- Zheng, Changge,Liu, Yang,Hong, Jianquan,Huang, Shuai,Zhang, Wei,Yang, Yupeng,Fang, Ge
-
supporting information
p. 1404 - 1407
(2019/05/01)
-
- Direct Transformation of Arylamines to Aryl Halides via Sodium Nitrite and N-Halosuccinimide
-
A one-pot universal approach for transforming arylamines to aryl halides via reaction with sodium nitrite (NaNO2) and N-halosuccinimide (NXS) in DMF at room temperature under metal- and acid-free condition is described. This new protocol that is complementary to the Sandmeyer reaction, is suggested to involve the in situ generation of nitryl halide induce nitrosylation of aryl amine to form the diazo intermediate which is halogenated to furnish the aryl halide.
- Mukhopadhyay, Sushobhan,Batra, Sanjay
-
p. 14622 - 14626
(2018/09/21)
-
- Palladium catalyzed stereocontrolled synthesis of C-aryl glycosides using glycals and arenediazonium salts at room temperature
-
A stereocontrolled synthesis of aryl-C-glycosides was achieved using glycals and aryldiazonium salts in the presence of palladium acetate. A wide range of glycals including d-glucal, d-galactal, l-rhamnal, d-xylal and d-ribal underwent C-arylation at the anomeric carbon in the presence of different aryldiazonium tetrafluoroborates and gave synthetically useful 2,3-deoxy-3-keto-α-aryl-C-glycosides in good to excellent yields. Broad substrate scope, simple operation and room temperature reactions make this protocol very attractive in organic synthesis.
- Singh, Adesh Kumar,Kandasamy, Jeyakumar
-
supporting information
p. 5107 - 5112
(2018/07/29)
-
- New transmetalation reagents for the gold-catalyzed visible light-enabled C(sp or sp2)-C(sp2) cross-coupling with aryldiazonium salts in the absence of a photosensitizer
-
The scope of photosensitizer-free visible light-driven gold-catalyzed cross-coupling was evaluated by a wide variety of organoboron and organosilicon species using four equivalents of aryldiazonium salts and (4-CF3-C6H4)3PAuCl in MeOH. In addition, a C(sp or sp2)-C(sp2) cross-coupling of organotrimethylsilanes and aryldiazonium salts was investigated. The reactions can be conducted under very mild reaction conditions, with a reduced amount of aryldiazonium salt (1.2 equiv.) by using a catalytic amount of Ph3PAuNTf2 in MeCN under irradiation with blue LEDs at room temperature.
- Witzel, Sina,Sekine, Kohei,Rudolph, Matthias,Hashmi, A. Stephen K.
-
supporting information
p. 13802 - 13804
(2018/12/14)
-
- Visible-Light-Promoted C-H Arylation by Merging Palladium Catalysis with Organic Photoredox Catalysis
-
The use of a dual palladium/organic photoredox catalytic system enables the directed arylation of arenes with aryldiazonium salts with a broad substrate scope at room temperature under mild reaction conditions. This study thus serves as not only an alternative route for the biaryl motifs but also a new example for the application of an organic photoredox catalyst.
- Jiang, Jian,Zhang, Wen-Man,Dai, Jian-Jun,Xu, Jun,Xu, Hua-Jian
-
p. 3622 - 3630
(2017/04/11)
-
- Cp?Ir(III)-Catalyzed Mild and Broad C-H Arylation of Arenes and Alkenes with Aryldiazonium Salts Leading to the External Oxidant-Free Approach
-
Reported herein is the development of Cp?Ir(III)-catalyzed direct C-H arylation of arenes and alkenes using aryldiazonium tetrafluoroborates, the use of which as an aryl precursor and also as an oxidant via C-N2 bond cleavage was a key to success in achieving a mild and external oxidant-free procedure. Mechanistic experiments and DFT calculations revealed the turnover-limiting step to be closely related to the formation of an Ir(V)-aryl intermediate rather than the presupposed C-H cleavage. Under the developed mild arylation conditions, a wide range of benzamides were smoothly arylated. In addition, synthetic utility of the current C-H arylation procedure was also demonstrated successfully for the (Z)-selective arylation of enamides and C8-selective reaction of quinoline N-oxides.
- Shin, Kwangmin,Park, Sung-Woo,Chang, Sukbok
-
supporting information
p. 8584 - 8592
(2015/07/15)
-
- Synthesis of difluoromethyl thioethers from difluoromethyl trimethylsilane and organothiocyanates generated in situ
-
A copper-CF2H complex generated in situ from copper thiocyanate and TMS-CF2H smoothly converts organothiocyanates into valuable difluoromethyl thioethers. This reaction step can be combined with several thiocyanation methods to one-pot protocols, allowing late-stage difluoromethylthiolations of widely available alkyl halides and arenediazonium salts. This strategy enables the introduction of difluoromethylthio groups - a largely unexplored substituent with highly promising properties - into drug-like molecules. A copper-CF2H complex generated in situ from copper thiocyanate and TMS-CF2H smoothly converts organothiocyanates into valuable difluoromethyl thioethers. This reaction step can be combined with several thiocyanation methods to one-pot protocols, allowing late-stage difluoromethylthiolations of widely available alkyl halides and arenediazonium salts.
- Bayarmagnai, Bilguun,Matheis, Christian,Jouvin, Kvin,Goossen, Lukas J.
-
supporting information
p. 5753 - 5756
(2015/06/10)
-
- One-Pot Reactions for Synthesis of 2,5-Substituted Tetrazoles from Aryldiazonium Salts and Amidines
-
One-pot sequential reactions of aryldiazonium salts with amidines followed by the treatment of I2/KI under basic conditions provide 2,5-disubstituted tetrazoles in moderate to excellent yields. This one-pot synthesis has several advantages such as mild reaction conditions, short reaction time, convenient workup, and high yields, making this methodology practical.
- Ramanathan, Mani,Wang, Yu-Hao,Liu, Shiuh-Tzung
-
supporting information
p. 5886 - 5889
(2015/12/11)
-
- An easy route to (hetero)arylboronic acids
-
An unprecedented spontaneous reactivity between diazonium salts and diboronic acid has been unveiled, leading to a versatile arylboronic acid synthesis directly from (hetero)arylamines. This fast reaction (35 min overall) tolerates a wide range of functional groups and is carried out under very mild conditions. The radical nature of the reaction mechanism has been investigated.
- Erb, William,Hellal, Akila,Albini, Mathieu,Rouden, Jacques,Blanchet, Jerome
-
supporting information
p. 6608 - 6612
(2014/06/09)
-
- A simple catalytic system based on PdCl2(CH3CN) 2 in water for cross-coupling reactions using diazonium salts
-
Aryl-heteroaryl and heteroaryl-heteroaryl compounds are obtained through the Suzuki-Miyaura cross-coupling reactions between diazonium salts and potassium trifluoroborates using PdCl2(CH3CN)2 as the catalyst in water and in the absence of any additive, ligand or base. In addition, the same mild catalytic system is effective for the Matsuda-Heck reaction between several monoolefins with aryldiazonium salts.
- El Bakouri, Ouissam,Fernández, Martí,Brun, Sandra,Pla-Quintana, Anna,Roglans, Anna
-
p. 9761 - 9765
(2013/10/22)
-
- A transition-metal-free synthesis of arylcarboxyamides from aryl diazonium salts and isocyanides
-
A transition-metal-free carboxyamidation process, using aryl diazonium tetrafluoroborates and isocyanides under mild conditions, has been developed. This novel conversion was initiated by a base and solvent induced aryl radical, followed by radical addition to isocyanide and single electron transfer (SET) oxidation, affording the corresponding arylcarboxyamide upon hydration of the nitrilium intermediate.
- Xia, Zhonghua,Zhu, Qiang
-
supporting information
p. 4110 - 4113
(2013/09/12)
-
- Rhodium(I)-catalyzed synthesis of aryltriethoxysilanes from arenediazonium tosylate salts with triethoxysilane
-
An efficient method for the preparation of aryltriethoxy-silanes from arenediazonium tosylate salts has been developed, which expands the substrates of rhodium-catalyzed silylation from iodides, bromides, and triflates to diazonium salts. A new method for hydrodediazoniation has also been explored.
- Tang, Zhi Yong,Zhang, Yuan,Wang, Tao,Wang, Wei
-
supporting information; experimental part
p. 804 - 808
(2010/06/14)
-
- Fischer indole synthesis with organozinc reagents
-
Updated classic: Primary and secondary alkylzinc reagents add to various aryldiazonium salts leading regioselectively to polyfunctional indoles by means of a [3,3]-sigmatropic shift and subsequent aromatization. This organometallic variation of the Fischer indole synthesis tolerates a wide range of functional groups and displays absolute regioselectivity. Copyright
- Haag, Benjamin A.,Zhang, Zhi-Guang,Li, Jin-Shan,Knochel, Paul
-
supporting information; experimental part
p. 9513 - 9516
(2011/02/24)
-
- Sandmeyer reactions. Part 7.1 An investigation into the reduction steps of Sandmeyer hydroxylation and chlorination reactions
-
For Sandmeyer hydroxylation and chlorination in aqueous solution, the reduction steps have been investigated by means of correlation analyses of the effects of diazonium ion substitution on the rates of reduction. For simple hydroxylation, a change of behaviour between diazonium ions substituted by electron donor groups and those substituted by electron acceptor groups is interpreted as a change within an inner-sphere process from rate-determining electron transfer to rate-determining association of the reactants. By contrast, for citrate-promoted hydroxylation, a similar change in behaviour may be interpreted as a change between inner- and outer-sphere electron transfers. For chlorination, there is no mechanistic variation within the range of substituents examined but the pattern of behaviour is consistent with an inner-sphere mechanism. The various patterns of behaviour are rationalised in terms of the effects of diazonium ion substitution and catalyst ligation on the reduction potentials and self-exchange rates of the various reacting redox couples. Comparative correlation analyses of reductions and other electrophilic reactions of diazonium ions are used to support the arguments advanced in respect of Sandmeyer reduction steps. It is suggested that the Cu1 reductants react via a nucleophilic bridging ligand at the diazonium Nβ to give transient Z-adducts which are the precursor complexes and that activation for electron transfer involves rotation about the N-N bond.
- Hanson, Peter,Jones, Jason R.,Taylor, Alec B.,Walton, Paul H.,Timms, Allan W.
-
p. 1135 - 1150
(2007/10/03)
-
- Classical Carbonium Ions. Part 12. The Deamination of 1- and 4-Amino-n-octane
-
The deamination products of 1- and 4-amino-octane in acetic acid were examined.The amines were treated with sodium nitrite directly, and also converted into alkylaryltriazenes derived from several arenediazonium cations, which were then acetolysed.N-Nitrosobutyramides were acetolysed, and N-nitrosoacetamides were butyrolysed, to allow the seperate analysis of rearranged and unrearranged products from internal and external nucleophiles.It is concluded that the primary alkylamine is converted by all these different methods in high yield into a primary alkane diazonium ion RN2+, the properties of which are independent of its method of preparation in that the alkyl cation formed by its decomposition does not capture the leaving group which accompanies its formation, but reacts with solvent to give a constant set of products.The secondary alkylamine behaves differently.Its diazo-derivatives, RN2X, usually undergo effectively concerted decomposition to carbonium ions, nitrogen, and leaving group X.The cations show differing degrees of hydride shift, and capture the internal nucleophile X to a considerable but variable extent, after as well as before rearrangement.The acetolysis of 4-diazo-octane proceeds via a much less reactive intermediate, possibly an intimate ion-pair, giving mainly unrearranged 4-acetoxyoctane, plus an olefin mixture in which the substantial proportion of cis-isomers reflects the conformational preference of the starting material.
- Southam, Richard M.,Whiting, Mark C.
-
p. 597 - 604
(2007/10/02)
-