Article
Chemistry, Multidisciplinary
Xue Zhang, Xiao-Bo Huang, Yun-Bing Zhou, Miao-Chang Liu, Hua-Yue Wu
Summary: This study presents a green method for synthesizing aryl selenocyanates under metal-free and additive-free conditions using arylboronic acids, Se powder, and trimethylsilyl cyanide (TMSCN) in a three-component reaction. Remarkably, TMSCN not only serves as a substrate but also as a catalyst, allowing access to various selenaheterocycles with a catalytic amount of TMSCN.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Makoto Sako, Kyohei Kanomata, Mohamed S. H. Salem, Tomohiro Furukawa, Hiroaki Sasai, Shinobu Takizawa
Summary: The nucleophilic addition and aryl migration of triarylphosphines to alkynyl esters in the presence of water leads to the formation of 3-(diarylphosphoryl)-3-aryl propanoic acid derivatives through a metal-free C(aryl)-P bond cleavage process. Experimental and computational investigations demonstrate that the rapid formation of hydroxy-lambda(5)-phosphane as a key intermediate plays a crucial role in facilitating the smooth C(aryl)-P bond cleavage.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Organic
Da-Liang Zhu, Jie Li, Qi Wu, Yanqing Wang, David J. Young, Hong-Xi Li
Summary: The efficient etherification of alcohols with aryl bromides can be promoted by sodium tert-butoxide at room temperature. This simple procedure offers a practical pathway to aryl alkyl ethers in good yields without the need for any transition metal species.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Minxiang Zhang, Hongyan Xie, Zhaohua Yan, Xueyu Fang, Yongsong Fang
Summary: A highly efficient method for deprotection of aryl alkyl ethers using iodotriphenylphosphonium iodide [Ph3P+I]I- formed in situ through the reaction of equimolar PPh3 and I2 was developed. Various aryl alkyl ethers including aryl methyl/allyl/benzyl/ethyl/n-propyl/ i-propyl/n-butyl ethers can all be deprotected to release the corresponding phenols in good to excellent yields.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Meng-Yang Chang, Kuan-Ting Chen
Summary: In this study, a high-yield method for synthesizing sulfonyl 2-aryl-5-methylenetetrahydropyrans is described. The method involves a one-pot DABCO-promoted intramolecular Michael addition and intramolecular alkylation, providing a highly effective stereoselective annulation by forming one carbon-oxygen bond and one carbon-carbon bond.
Article
Chemistry, Multidisciplinary
Yan Zheng, Bing-Hong Teng, Youcan Zhang, Xiao-Feng Wu
Summary: In this study, a photo-induced metal-free carbonylation reaction of aryl bromides was developed. The reaction showed good reactivity with alcohol and amine nucleophiles, and a variety of useful aryl esters and amides were synthesized at room temperature in moderate to good yields.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Yongjin Guo, Hongpeng Bao, Liyuan Chen, Jiarong Shi, Yang Li
Summary: An insertion reaction of benzyne into the Se=O bond has been successfully achieved, leading to the synthesis of two different types of selenium-containing compounds from various substrates.
Article
Chemistry, Organic
Kwihwan Kobayashi, Shingo Komatsuzaki, Shun-ya Onozawa, Koichiro Masuda, Shu Kobayashi
Summary: We present a green method for the synthesis of aryl enol ethers from phenols and dimethyl ketals using aluminium as a catalyst, without halides and transition metals. The ketal exchange reaction is driven by the removal of methanol. The obtained aryl enol ethers can be transformed into diaryl ethers through Pd/C-catalysed dehydrogenation or DDQ oxidation. This method is significant for the synthesis of important intermediates or building blocks in organic synthesis and polymer chemistry.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Organic
Kwihwan Kobayashi, Shingo Komatsuzaki, Shun-ya Onozawa, Koichiro Masuda, Shu Kobayashi
Summary: We present an aluminium-catalysed, halide- and transition metal-free method for synthesizing aryl enol ethers from phenols and dimethyl ketals through ketal exchange driven by methanol removal. The obtained aryl enol ethers can be further transformed into diaryl ethers using Pd/C-catalysed dehydrogenation or DDQ oxidation. This new protocol provides a halide- and transition metal-free approach for the synthesis of phenols and dimethyl ketals, which are important intermediates or building blocks in organic synthesis and polymer chemistry.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2023)
Article
Chemistry, Physical
P. Hima, M. Vageesh, Michele Tomasini, Albert Poater, Raju Dey
Summary: A transition metal-free synthesis of quinazoline derivatives from 2-aminobenzyl alcohols and aryl amides using a potassium tertiary butoxide-promoted alcohol dehydrogenation strategy is reported. Control experiments were conducted to identify reaction intermediates and the role of the K+ ion. DFT calculations uncovered the reaction mechanism, focusing on the rate-determining state. This method tolerates various functional groups, providing easy access to diversely substituted quinazolines.
MOLECULAR CATALYSIS
(2023)
Article
Chemistry, Organic
Venkata Hema Kumar, Sannapaneni Janardan, Ramana Tamminana
Summary: This study describes the metal-free synthesis of tetrazoles in the presence of open air at room temperature. By reacting 2-bromoaryl isothiocyanates with amines, thiourea is formed, which then undergoes substitution and electrocyclization reactions in the presence of water and Iodine to produce 1-(2-bromophenyl)-N5-arylaminotetrazoles. The reaction successfully yielded the desired products with moderate to good yields, and the method was also applicable for large-scale synthesis. Additionally, the use of aqueous micellar medium showed good recyclability and high product yield for multiple cycles.
TETRAHEDRON LETTERS
(2023)
Article
Chemistry, Organic
Chenchen Li, Qi Qin, Aocong Guan, Wen Yang, Wanxiang Zhao
Summary: We present a general and efficient transition-metal-free C-C bond cross-coupling reaction of (hetero)-aryl ethers and diarylmethanes via C-(sp(2))-O bond cleavage. The coupling reactions mediated by KHMDS demonstrated high efficiency, broad substrate scope, and good functional group tolerance. The robustness and practicality of this protocol were further demonstrated by gram-scale preparation and diversified product derivatization.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Xi Cheng, Da-Bin Qin, Zhi-Bing Dong
Summary: An efficient three-component synthesis of disubstituted 4-aryl-2-aminothiazoles was reported. The protocol features transition-metal free, short reaction time, easily available starting materials, good yields, and broad substrate scope, showing potential synthetic value for the synthesis of a variety of biological or pharmaceutical active compounds.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Qing-Wen Gui, Bin-Bin Wang, Sha Zhu, Fu-Long Li, Meng-Xue Zhu, Min Yi, Jia-Ling Yu, Zhi-Lin Wu, Wei-Min He
Summary: This study efficiently synthesized various 3-aminomethylated imidazoheterocycles in one step using green ethanol as the sole solvent, under metal-free, oxidant-free, and mild conditions with cheap and commercially available reactants.
Article
Chemistry, Organic
Arijit Hazra, Raghunath Dey, Apoorv Kushwaha, T. J. Dhilip Kumar, Prabal Banerjee
Summary: For the first time, an organocatalytic enantioselective (3+3)-cycloaddition reaction of racemic cyclopropane carbaldehydes and aryl hydrazones has been demonstrated. Enantioenriched tetrahydropyridazines with an exocyclic double bond were obtained in moderate to good yields and with good to excellent enantiomeric excesses. Mechanistic investigations suggested a matched/mismatched kinetic resolution, and control experiments and DFT calculations revealed that 1,3-aryl migration is concerted and intramolecular, proceeding through a four-membered transition state.
Article
Chemistry, Multidisciplinary
Serena Monticelli, Wolfgang Holzer, Thierry Langer, Alexander Roller, Berit Olofsson, Vittorio Pace
Article
Chemistry, Multidisciplinary
Laura Castoldi, Ester Maria Di Tommaso, Marcus Reitti, Barbara Grafen, Berit Olofsson
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Multidisciplinary
Gabriella Kervefors, Leonard Kersting, Berit Olofsson
Summary: A transition metal-free approach using unsymmetric diaryliodonium salts with anisyl ligands has been developed for the N-arylation of amino acid derivatives, achieving high chemoselectivity and yields. This method is applicable for transferring electron deficient, electron rich, and sterically hindered aryl groups, and a cyclic diaryliodonium salt was successfully employed. The N-arylated products were obtained with retained enantiomeric excess.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Gabriella Kervefors, Kumar Bhaskar Pal, Gergely L. Tolnai, Mukul Mahanti, Hakon Leffler, Ulf J. Nilsson, Berit Olofsson
Summary: The study focused on synthesizing a series of O3-arylated galactosides and their inhibitory effects on galectin-3, leading to the discovery of a compound with promising affinity and selectivity for both the N- and C-terminal domains of galectin-9.
HELVETICA CHIMICA ACTA
(2021)
Article
Chemistry, Multidisciplinary
Erika Linde, David Bulfield, Gabriella Kervefors, Nibadita Purkait, Berit Olofsson
Summary: This study combines nucleophilic aromatic substitution and hypervalent iodine-mediated arylations to achieve a transition-metal-free difunctionalization of N and O-nucleophiles, providing di-and triarylamines and diaryl ethers in one single step. The unique reactivity discovered with specifically designed fluorinated diaryliodonium salts unveils novel reaction pathways in hypervalent iodine chemistry. The methodology tolerates a wide variety of functional and protecting groups, allowing for easy derivatization of the products.
Article
Chemistry, Multidisciplinary
Ester M. Di Tommaso, Per-Ola Norrby, Berit Olofsson
Summary: Vinylbenziodoxolones have been identified as efficient reagents for electrophilic vinylations under metal-free conditions. This paper presents the first mechanistic investigation of VBX vinylations, providing insights into the regio- and stereochemical outcome. The findings can be applied to predict the regioselectivity in vinylations of other nucleophile classes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Erika Linde, Niels Knippenberg, Berit Olofsson
Summary: Two regioselective and high-yielding methods for the synthesis of oxygen-bridged cyclic and ortho-aryloxy-substituted acyclic diaryliodonium salts were presented. These novel compounds exhibited complimentary reactivities in chemoselective arylation reactions, delivering a range of novel ortho-functionalized diaryl ether derivatives.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Shobhan Mondal, Ester Maria Di Tommaso, Berit Olofsson
Summary: Efficient protocols for accessing iodo-substituted diaryl and aryl(vinyl) sulfides have been developed using iodonium salts as reactive electrophilic arylation and vinylation reagents. The reactions take place under transition-metal-free conditions, employing odorless and convenient sulfur reagents. A wide variety of functional groups are tolerated in the S-diarylation, enabling the regioselective late-stage application of several heterocycles and drug molecules under mild reaction conditions. A novel S-difunctionalization pathway was discovered using vinyliodonium salts, which proceeds under additive-free reaction conditions and grants excellent stereoselectivity in the synthesis of aryl(vinyl) sulfides. A one-pot strategy combining transition-metal-free diarylation and subsequent reduction provided facile access to electron-rich thioanilines and a direct synthesis of a potential drug candidate derivative. The retained iodo group allows a wide array of further synthetic transformations. Mechanistic insights were elucidated by isolating the key intermediate, and the relevant energy profile was substantiated by DFT calculations.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Erika Linde, Shobhan Mondal, Berit Olofsson
Summary: Our group has developed new methods for the synthesis of diaryliodonium salts, which are versatile reagents in organic synthesis and materials chemistry. We have identified limitations in the existing protocols for synthesizing different types of diaryliodonium salts. In this update, we discuss the challenges related to the stability and reactivity of the reagents and propose strategies to overcome these limitations.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Kumar Bhaskar Pal, Ester Maria Di Tommaso, A. Ken Inge, Berit Olofsson
Summary: We report an efficient radical-mediated C-C coupling through photoredox-catalyzed reactions of 4-alkyl-dihydropyridines (DHPs) and vinylbenziodoxol(on)es (VBX, VBO). This transition-metal-free and mild photocatalytic method has excellent functional group tolerance and affords vinylated products in good yields, with complete retention of the alkene configuration. The utility of the methodology is demonstrated by the diastereoselective synthesis of C-vinyl glycosides. Preliminary mechanistic studies suggest that the C-C bond formation is stereospecific and proceeds through a concerted radical coupling transition state.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Editorial Material
Chemistry, Multidisciplinary
Shobhan Mondal, Berit Olofsson
TRENDS IN CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Erika Linde, Berit Olofsson
Summary: The diarylation and skeletal diversification of unstrained cyclic amines was explored to expand and modify their properties. A novel class of amino-substituted diaryliodonium salts was synthesized from cyclic amines and converted to highly functionalized diarylamines through a one-pot N-arylation/ring opening reaction. This strategy proved efficient in the late-stage functionalization of natural products and pharmaceuticals, and provided a wide variety of complex diarylamines. The method involves the introduction of two different aryl groups and the retention of an iodo-substituent, allowing for downfield diversification of the products.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Ester Maria Di Tommaso, Melanie Walther, Anne Staubitz, Berit Olofsson
Summary: This study developed a synthetic route to access ortho-substituted azobenzenes via novel ortho-substituted azobenzene-functionalized diaryliodonium salts. The selective transfer of the azobenzene moiety to various nucleophiles enables the synthesis of a wide range of ortho-substituted azobenzenes. The photoswitching properties and crystal structure of the reagents were investigated.
CHEMICAL COMMUNICATIONS
(2023)
Article
Biochemical Research Methods
Erika Linde, Berit Olofsson
Summary: An efficient protocol for the diarylation of aliphatic amines and water with two structurally different aryl groups in one single step was presented, yielding highly functionalized products.
Article
Chemistry, Multidisciplinary
Laura Castoldi, Adam A. Rajkiewicz, Berit Olofsson
CHEMICAL COMMUNICATIONS
(2020)