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, Multidisciplinary
Andreu Tortajada, Leonie J. Bole, Manting Mu, Martin Stanford, Marconi N. Penas-Defrutos, Max Garcia-Melchor, Eva Hevia
Summary: By using a sodium base in combination with the tridentate Lewis donor PMDETA and the sterically demanding electrophilic trap B(CH2SiMe3)(3), the deprotonative borylation of arenes can be achieved, resulting in the formal borylation of two equivalents of the relevant arene. The first B-C bond formation occurs through a sodiation/borylation sequence, while the second borylation step is facilitated by the formation of a borata-alkene intermediate.
Article
Chemistry, Multidisciplinary
Amelia Messara, Armen Panossian, Koichi Mikami, Gilles Hanquet, Frederic R. Leroux
Summary: The deprotonative functionalization of alpha,alpha-difluoromethyl ketones is achieved by using a catalytic organosuperbase and a silane additive, leading to the generation of difluoroenolates that can be trapped with aldehydes to produce alpha,alpha-difluoro-beta-hydroxy ketones. This strategy allows for the direct deprotonation of the difluoromethyl unit and is tolerant of various functional groups. The diastereoselective version of the reaction was also explored, with high diastereomeric ratios. Several transformations demonstrate the synthetic potential of these alpha,alpha-difluoro-beta-hydroxy ketones. Additionally, the method can be extended for the use of other electrophiles and nucleophiles, resulting in a diversity of difluoromethylene compounds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Xinyu Chen, Na Yang, Wen Zeng, Lei Wang, Pinhua Li, Hongji Li
Summary: A mild dearomative [5+2]/[2+2] cycloaddition of 1H-indoles with ortho-(trimethylsilyl)aryl triflates was reported, leading to the synthesis of dibenzo[b,e]azepine derivatives in moderate to good yields. Increasing steric hindrance at the C2-position of 1H-indoles directs the reaction towards a [2+2] cycloaddition pathway. Mechanistic investigations suggest that the reaction proceeds through a [2+2] cycloaddition followed by a ring expansion to form the [5+2] cycloaddition product.
CHEMICAL COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Nurbey Gulia, Jaroslaw Fornalski, Adrianna Gumienna, Malgorzata Ambroziak, Slawomir Szafert
Summary: This study reports a method of palladium-catalyzed C-H arylation assisted with a 3,4,4-trimethylpyrazol-5-on directing group, which selectively provides mono- and di-ortho-arylated products. The steric hindrance between the directing group and the already introduced aryl substituent enables control of mono- vs. diarylation selectivity by the reaction temperature. A series of monosubstituted and disubstituted derivatives were obtained in good yields. In addition, a one-pot procedure for unsymmetrical double-arylation to give corresponding products was developed, and the synthesis and X-ray study of intermediate palladium metallacycles were conducted. The decarboxylative cleavage of the pyrazolone directing group under mild conditions gave synthetically useful hydrazones. Overall, this solution provides an alternative synthetic pathway for ortho arylated derivatives of arylhydrazines.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Hongpeng Bao, Yongjin Guo, Jiarong Shi, Yang Li
Summary: Two sets of cascade processes were achieved by benzyne insertion into the Se=O bond. The differential factors in these processes are the structures of diaryl selenium oxides and reaction conditions. When diaryl selenium oxides with an ortho weak Sigma- electron-withdrawing group were used, triarylselenonium salts were obtained at room temperature, while ortho-(aryloxy)phenyl phenyl selanes could be produced from diaryl selenium oxides at 100 degrees C.
Article
Chemistry, Organic
Sujin Bak, Yeri Son, Sunjoo Hwang, Ha Eun Kim, Jun-Ho Choi, Won-jin Chung
Summary: Our group has developed a method for synthesizing alpha-fluoroamines using dioxaphospholenes derived from various 1,2-diketones and dealkylation-resistant phosphoramidite as carbene surrogates, enabling insertion into the N-F bond of (PhSO2)(2)NF. This paper presents the scope and limitations of the reaction and site selectivity, rationalized through computational analysis. Additionally, efforts to broaden the synthetic utility of the method by incorporating other nitrogen nucleophiles and halogen electrophiles are described.
SYNTHESIS-STUTTGART
(2023)
Article
Chemistry, Organic
Xiuwen Jia, Liping Luo, Chunxi Huang, Xuemei Zhang, Zhong Lian
Summary: An iron-catalyzed four-component sulfonylthiocyanation reaction has been demonstrated, providing a feasible method for the preparation of beta-thiocyanated sulfone compounds. The reaction conditions are mild, with good functional group compatibility and broad substrate scope. Preliminary mechanistic investigation suggests the involvement of a radical pathway.
Article
Chemistry, Multidisciplinary
Wen-Xuan Cao, Lei Zhu, Yiyi He, Run Wang, Ming Liu, Qin Ouyang, Qing Xiao
Summary: The first aryne insertions into the carbon-iodine bond of heteroaryl iodides have been achieved. This novel reaction provides an efficient pathway for the synthesis of valuable building blocks 2-iodoheterobiaryls with excellent regioselectivity by reacting heteroaryl iodides and o-silylaryl triflates. The copper(I) catalyst, which contains a N-heterocyclic carbene (NHC) ligand, is essential for the reaction. Control reactions and DFT calculations suggest that the coordination of copper, acting as a Lewis acid, with nitrogen atoms of heteroaryl iodides mediates the aryne insertions into heteroaryl carbon-iodine bonds.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Yi-Ming Wei, Xiao-Di Ma, Xin-Fang Duan
Summary: This article briefly discusses various methods for ortho difunctionalization of arenes and highlights a novel ortho-heterobimetallic arylene complex enabled by heterobimetallic synergism, which shows great potential in regioselective ortho difunctionalizations.
Article
Chemistry, Physical
Shucheng Ma, Fangjie Li, Guisheng Zhang, Lei Shi, Xiaoming Wang
Summary: A nickel-catalyzed reaction has been developed for the synthesis of 1,4-difluoroalkylarylation products from 1,3-butadiene with easily accessible difluoroalkyl bromides and arylboronic acids. The involvement of a key alkyl radical in the catalysis was demonstrated by a radical clock experiment. The operational simplicity, excellent functional-group compatibility, and high efficiency of this three-component reaction make it highly promising for the cost-efficient synthesis of difluoroalkylated compounds.
Article
Chemistry, Organic
Albert Artigas, Denis Hagebaum-Reignier, Yannick Carissan, Yoann Coquerel
Summary: Visualization of electron delocalization and aromaticity in selected aryne compounds, including nonplanar examples, and their reactions was achieved using multidimensional isotropic magnetic shielding contour maps. The maps showed that aryne compounds are generally less aromatic than the corresponding arene compounds, with aromaticity peaking during the reaction when approaching the transition state.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Organic
Jason R. Combs, Yin-Chu Lai, David L. Van Vranken
Summary: Allyl 2-diazo-2-phenylacetates react with trimethylsilyl thioethers in the presence of rhodium(II) catalysts to generate alpha-allyl-a-thio silyl esters. The reaction involves a tandem process of carbene group insertion into the S-Si bond and Ireland-Claisen rearrangement. The products are isolated as carboxylic acids after aqueous workup, with intramolecular cyclopropanation and heteroatom addition competing during the reaction.
Article
Chemistry, Multidisciplinary
Yuan-Yuan Cheng, Hong-Yu Hou, Yu Liu, Ji-Xin Yu, Bin Chen, Chen-Ho Tung, Li-Zhu Wu
Summary: This paper reports a direct strategy for the difunctionalization of alkenes using a single photocatalyst. The strategy allows for acylation at the more substituted alkene position with high chemo- and regioselectivity under extremely mild conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Seoyoung Cho, E. J. McLaren, Qiu Wang
Summary: The difunctionalization of strained cyclic alkynes provides a powerful strategy to construct diverse cyclic alkenes. A new approach using a zincate base/nucleophile system has been demonstrated for efficient formation of cyclohexyne intermediates and selective addition of various carbon and nitrogen nucleophiles, enabling the synthesis of structurally diverse cyclohexene motifs. The modularity and ease of access to highly complex polycyclic scaffolds in one step highlight the importance and utility of this method.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.