Potassium Aryltrifluoroborates Research Articles

C(sp2)−C(sp2) Coupling in Water: Palladium(II) Complexes of N‐Pincer Tetradentate Porphyrins as Effective Catalysts

AbstractA convenient and efficient palladium(II)–porphyrin catalytic system has been developed for the Suzuki–Miyaura cross‐coupling (SMC) of aryl bromides with potassium aryltrifluoroborate in water. A series of seven different porphyrins and their complexes with palladium (PdII(por)‐1–PdII(por)‐7) were prepared, and screened their catalytic activity in making biaryls through C(sp2)−C(sp2) coupling. Significantly, the present protocol utilizes safe, water‐soluble, and highly stable porphyrins as an alternative to toxic and unstable phosphine ligands. The simple preparation of porphyrins and their complexes, use of moisture‐resistant catalyst, excellent yields of the isolated products, use of eco‐friendly solvent (such as water), and reusability of the catalyst are the notable advantages of this method. This finding uses marginally explored, moisture‐insensitive potassium phenyltrifluoroborates as nucleophiles for SMC. Furthermore, the scope of the method has been demonstrated for the multi‐gram scale preparation of biaryls without any side products.

An Optimized and General Synthetic Strategy To Prepare Arylnaphthalene Lactone Natural Products from Cyanophthalides

A simple method for the preparation of arylnaphthalene lactone natural products was developed and used to synthesize diphyllin (10), justicidin A (12), cilinaphthalide B (13), taiwanin E (15), chinensinaphthol (16), taiwanin E methyl ether (17), chinensinaphthol methyl ether (18), justicidin C (21), and justicidin D (22). Key steps of the syntheses include the Hauser–Kraus annulation of cyanophthalides 7a and 7b and Suzuki–Miyaura cross‐coupling reactions between arylnaphthalene lactones that contain a sulfonate group (i.e., 9, 14, 19, and 20) and various potassium aryltrifluoroborates.

Sonication and Microwave-Assisted Primary Amination of Potassium­ Aryltrifluoroborates and Phenylboronic Acids under Metal-Free Conditions

The transition-metal-free generation of a series of primary arylamines from potassium aryltrifluoroborates and phenylboronic acids­ is reported. The method uses a mild, inexpensive source of nitrogen (hydroxylamine-O-sulfonic acid) in cooperation with aqueous sodium hydroxide in acetonitrile. Both a sonication and a microwave-assisted method were developed, which are capable of converting ArBF3K functionalities into primary arylamines (ArNH2) in isolated yields of up to 78% (10 examples for each method). This report represents the first general method for the conversion of aryltrifluoroborates into primary arylamines under mild, transition-metal-free conditions in moderate to very good yields. The method is applicable to a wide array of substrates containing electron-donating, electron-neutral, or electron-withdrawing substituents. Both the sonication and microwave methods were also applied to the generation of anilines from phenylboronic acids in isolated yields of up to 96% (12 examples for each method) that were superior to existing room temperature methods in terms of yield, while also offering much shorter reaction times (15 min vs 16 h). In particular, the microwave method is the first to allow for the conversion of arylboronic acids containing strongly electron-withdrawing substituents into the corresponding anilines in good yields, along with electron-donating­ substituents in very good to excellent yields.

Palladium-catalyzed tandem addition/cyclization in aqueous medium: synthesis of 2-arylindoles.

An efficient protocol to construct 2-arylindoles was developed through palladium-catalyzed tandem addition/cyclization of potassium aryltrifluoroborates with aliphatic nitriles in aqueous medium. The use of water as the reaction medium makes the synthesis process environmentally benign. A plausible mechanism for the formation of 2-arylindoles involving sequential nucleophilic addition followed by an intramolecular cyclization is proposed. Moreover, the utility of this catalytic tandem transformation was also demonstrated in an efficient gram-scale synthesis. This method provides an alternative synthetic tool for accessing a more diverse array of 2-arylindoles.

ChemInform Abstract: Ligand‐Free Palladium‐Catalyzed Oxidative Carbonylative Homocoupling of Arylboron Reagents at Ambient Pressure.

AbstractIn contrast to traditional metal‐based oxidative systems the developed homo‐coupling of aryl boronic acids or potassium aryltrifluoroborates uses molecular oxygen or iodine as the oxidant, respectively.

Homocoupling reactions of terminal alkynes and arylboronic compounds catalyzed by in situ formed Al(OH)3-supported palladium nanoparticles

Palladium nanoparticles supported on newly generated Al(OH)3 was found to be a highly efficient catalyst in oxidative homo-couplings of (Het)aryl alkynes, (Het)arylboronic acids and potassium (Het)aryltrifluoroborates, respectively. Moderate to excellent yields of symmetrical 1,3-diynes and biaryls were obtained under mild conditions.

ChemInform Abstract: Oxygen‐Promoted Pd/C‐Catalyzed Suzuki—Miyaura Reaction of Potassium Aryltrifluoroborates.

AbstractA simple, efficient and ligand‐free protocol for the Suzuki—Miyaura reaction is developed and successfully applied for the synthesis of aryl‐substituted 9‐phenylcarbazole derivatives such as (IIIi) and (IIIj).

Ligand‐Free Palladium‐Catalyzed Oxidative Carbonylative Homocoupling of Arylboron Reagents at Ambient Pressure

Arylboronic acids or potassium aryltrifluoroborates were readily oxidatively carbonylated to their corresponding diaryl ketones in high yields with high selectivities by ligand‐free palladium‐catalyzed homocoupling at atmospheric pressure. This novel method employs molecular oxygen or iodine as the oxidant and offers an attractive alternative to transition‐metal‐based oxidant systems.

ChemInform Abstract: Copper‐Mediated Oxidative Trifluoromethylthiolation of Potassium Aryltrifluoroborates with Elemental Sulfur and Ruppert—Prakash Reagent.

A facile procedure for the copper-mediated oxidative trifluoromethylthiolation of potassium aryl- and heteroaryltrifluoroborates with Ruppert–Prakash reagent and elemental sulfur is presented. Aryl trifluoromethyl thioethers can be prepared in good to moderate yield under mild reaction conditions.

Copper-Mediated Oxidative Trifluoromethylthiolation of Potassium Aryltrifluoroborates with Elemental Sulfur and Ruppert–Prakash Reagent

A facile procedure for the copper-mediated oxidative trifluoromethylthiolation of potassium aryl- and heteroaryltrifluoroborates with Ruppert–Prakash reagent and elemental sulfur is presented. Aryl trifluoromethyl thioethers can be prepared in good to moderate yield under mild reaction conditions.

Oxygen-promoted Pd/C-catalyzed Suzuki–Miyaura reaction of potassium aryltrifluoroborates

Abstract A simple and highly efficient protocol has been developed for the Pd/C-catalyzed ligand-free Suzuki–Miyaura reaction of potassium aryltrifluoroborates. In this catalytic system, the results demonstrate that oxygen plays a positive role in the cross-coupling reaction. In addition, this catalytic system could be successfully applied to synthesize biaryl compounds containing a carbazole moiety and the catalyst was recycled seven times without significant loss of catalytic activity.

Palladium-Catalyzed Ligand-Free Suzuki Reaction of Potassium Aryltrifluoroborates in Aqueous Ethanol

A simple and ligand-free protocol has been developed for the Pd(OAc)2-catalyzed Suzuki reaction of potassium aryltrifluoroborates in aqueous ethanol under air. In the presence of Pd(OAc)2 and 1 equiv. of K2CO3, aryl or heteroaryl halides coupled with various potassium aryltrifluoroborates smoothly to afford the products in high yields with the highest turnover frequency (TOF) up to 4656 h -1 , and a series of triphenylamine derivatives were prepared efficiently in this system. In addi- tion, the active catalyst was proved to be the in situ-generated palladium nanoparticles according to TEM analysis and mercu- ry-poisoning test. Keywords palladium; ligand-free; Suzuki reaction; potassium aryltrifluoroborates; aqueous ethanol

Microwave Application and Anhydrous Cu(OAc)2 Mediated O-Arylation of Aliphatic Amino Alcohols.

Anhydrous Cu(OAc)2 mediated efficient protocol has been developed in the area of C-O coupling from potassium aryltrifluoroborates and aliphatic amino alcohols such as β-hydroxy, γ-hydroxy, and δ-hydroxy amines. The scope of this transformation focuses on direct O-arylation and Ostyrylation. The reaction vial loaded with reactants under argon atmosphere is microwaved at 140°C for 30 min to furnish the corresponding cross-coupling product, amino ethers, in good yields.

Palladium-catalyzed decarboxylative alkoxycarbonylation of potassium aryltrifluoroborates with potassium oxalate monoesters

An efficient method for the preparation of aryl esters has been developed via Pd-catalyzed decarboxylative coupling of potassium aryltrifluoroborates and potassium oxalate monoesters.

Copper-mediated N-arylation of methyl 2-aminothiophene-3-carboxylate with organoboron reagents

A practical protocol for the synthesis of N-arylated methyl 2-aminothiophene-3-carboxylate has been developed via Chan–Lam cross-coupling. The desired products were synthesized by cross-coupling of methyl 2-aminothiophene-3-carboxylate with both arylboronic acids and potassium aryltrifluoroborate salts in moderate to good yields. A broad range of functional groups was well tolerated.

ChemInform Abstract: Rhodium‐Catalyzed Synthesis of Aryl Ketones from Carboxylic Acid Anhydrides and Potassium Aryltrifluoroborates in the Presence of CuI.

AbstractAliphatic carboxylic anhydrides do not react with potassium phenyltrifluoroborate under the reaction conditions.

ChemInform Abstract: In situ‐Generated Nano‐Palladium‐Catalyzed Ligand‐Free Suzuki—Miyaura Reaction of Potassium Aryltrifluoroborates at Room Temperature.

ChemInformVolume 46, Issue 37 Isocyclic Compounds ChemInform Abstract: In situ-Generated Nano-Palladium-Catalyzed Ligand-Free Suzuki—Miyaura Reaction of Potassium Aryltrifluoroborates at Room Temperature. Chun Liu, Chun Liu State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorXinmin Li, Xinmin Li State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorZhanming Gao, Zhanming Gao State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorXinnan Wang, Xinnan Wang State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorZilin Jin, Zilin Jin State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this author Chun Liu, Chun Liu State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorXinmin Li, Xinmin Li State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorZhanming Gao, Zhanming Gao State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorXinnan Wang, Xinnan Wang State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this authorZilin Jin, Zilin Jin State Key Lab. Fine Chem., Dalian Univ. Technol., Dalian 116024, Peop. Rep. ChinaSearch for more papers by this author First published: 27 August 2015 https://doi.org/10.1002/chin.201537109Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume46, Issue37September, 2015 RelatedInformation

ChemInform Abstract: Novel SF5‐Anilines and SF5‐Aryl Ethers from SF5‐Substituted Potassium Aryl Trifluoroborates.

Abstract3‐SF5‐aryl ether (IX) and (X) are obtained by Chan—Lam—Evans coupling reaction of phenols and alkyl alcohols with SF5‐substituted potassium aryltrifluoroborates.

ChemInform Abstract: Weakly Nucleophilic Potassium Aryltrifluoroborates in Palladium‐Catalyzed Suzuki—Miyaura Reactions: Relative Reactivity of K[4‐RC6F4BF3] and the Role of Silver‐Assistance in Acceleration of Transmetalation.

ChemInform Abstract: Weakly Nucleophilic Potassium Aryltrifluoroborates in Palladium‐Catalyzed Suzuki—Miyaura Reactions: Relative Reactivity of K[4‐RC₆F₄BF₃] and the Role of Silver‐Assistance in Acceleration of Transmetalation.

Palladium-catalyzed efficient Suzuki–Miyaura reaction of potassium aryltrifluoroborates in water

An efficient and environment-friendly protocol has been developed for the palladium-catalyzed Suzuki–Miyaura reaction of potassium aryltrifluoroborates with (hetero)aryl halides in water without any additive. This method allows the preparation of a variety of biaryls and heterobiaryls in excellent yields. In addition, the cross-coupling product can be isolated in good yields and high purity by simple filtration and recrystallization as the reaction was performed on gram scale.