Latest ArticlesA practical synthesis of α-bromo/iodo/chloroketones from olefins under visible-light irradiation conditions has been developed. In the presence of PhI(OAc)2 as promoter and under ambient conditions, the reactions of styrenes and triiodomethane undergo the transformation smoothly to deliver the corresponding α-iodoketones without additional photocatalyst in good yields under sunlight irradiation. Meanwhile, the reactions of styrenes with tribromomethane and trichloromethane generate the desired α-bromoketones and α-chloroketones in high yields by using Ru(bpy)3Cl2 as a photocatalyst under blue LED (450–455 nm) irradiation.
An efficient synthesis of 3-(diarylallylidene)oxindoles from 3-(1H-indol-3-yl)-1, 1-diarylpropan-1-ol under metal-free conditions is described. NBS serves as a critical medium leading to a facile oxygen-migration in the transformation. The protocol has advantages of high efficiency, simple opreation, mild reaction conditions, good atom-economy, wide substrate scope and good yields of products. A detailed mechanism is proposed after careful investigation.
A palladium-catalyzed [4 + 1] cycloaddition of prop-2-yn-1-ones with double isocyanides is developed herein. The transformation worked well to produce a series of 2-amino-4-cyanofurans with high efficiency and a broad reaction scope. Based on mechanism studies, it is believed that the palladium-catalyzed [4 + 1] imidoylative cycloaddition of prop-2-yn-1-ones was concerted. Treated with aryl amine and H2O, the [4 + 1] cycloaddition of prop-2-yn-1-ones with double isocyanides provided 2-amino-4-amidylpyrroles efficiently.
Experiments indicate that a catalytic amount of CuI plays an important role in the siloxane-mediated Pd-catalyzed cross-coupling reactions with the direct use of organolithium reagents. Addition of organolithium to the siloxane transfer agent generates an organosilicon intermediate. DFT calculations indicate that CuI initially accelerates the Si-Pd(Ⅱ) transmetalation of the organosilicon intermediate by the formation of CuI2-. Subsequently, CuI2- works as a shuttle between the Si-Cu(I) and Cu(I)-Pd(Ⅱ) transmetalation processes.
To discover novel fluorophores of solution and solid dual-state emission (DSE) materials, unique V-shape furo[2, 3-b]furans have been designed and synthesized by a one-pot method for the first time and their photoluminescent properties have been explored in benzene, THF, DMF and DMSO, as well as in the solid state. As the best example, 2, 5-bis(4-(9H-carbazol-9-yl)phenyl)-6a-amino-3a, 6a-dihydrofuro[2, 3-b] furan-3, 3a, 4-tricarbonitrile (3g) exhibited solution and solid DSE properties in THF, benzene, and in the solid state with quantum yields of 55%, 92%, and 45%, respectively.
A cascade carbonylative ring expansion and [2 + 2]/[4 + 2] cycloaddition of strained 1-iminylphosphirane complexes with aryl allenes were reported. The carbonylative ring expansion of 1-iminylphosphirane complexes provides an azaphosphacyclohexone complex intermediate with a C＝P double bond. The following [2 + 2] or dearomatic [4 + 2] cycloaddition of this intermediate with allenes is modulated by the aryl substituents on the imino carbon. The regioselective [2 + 2] cycloaddition with 1, 1-diarylallene provides an entry to bicyclo[4.2.0]octan-4-one skeletons featuring a four-membered phosphacyclobu-tane moiety. While dearomatic [4 + 2] cycloaddition was preferred with less aromatic naphthalene and yielded octahydrochrysene skeleton containing heteroatoms.
S-Monofluoromethyl phosphorothioates represent an important class of organofluorine compounds and are reported here for the first time. A series of S-monofluoromethyl phosphorothioates are conveniently synthesized from different PV-H compounds and PhSO2SCH2F under mild conditions. The method is compatible with common functional groups and provides potential opportunities to synthesize new bioactive molecules for medicinal chemistry.
Both racemate and enantiomer of a novel double helix, binaphthylcyclooctaterthiophene (BN—COTh), which is a DNA-like molecule constructed by two single helices intertwined with each other via covalent bonds, have been synthesized with two building blocks, cycloocta-tetrathiophene (COTh) and cyclooctadinaphthyldithiophene (CONT) fused together via Negishi coupling reaction. Another homologue, dinaphthylcyclooctaterthiophene (DN-COTh) has been employed together as a model compound. Besides the synthetic work, BN—COTh and DN-COTh have been investigated by studying their crystal structures, spectroscopic behaviors, chiral resolution and chiral characteristics, including circular dichroism (CD) spectra and optical rotations. In addition, the novel crystal of enantiomer of (R, R, R)-BN—COTh has been explored. The enantiomer molecules packing along b-axis to form a larger and extended assembly packing due to intermolecular interactions between the enantiomer molecules and chloroform molecules in crystal.
The cheap and easily available sodium dithionite and thiourea dioxide have been used as the source of sulfonyl group in the synthesis of sulfones and sulfonamides recently. Compared with other methods for the sulfonylation reactions, the strategies using sodium dithionite or thiourea dioxide provide an alternative and complementary route to diverse sulfonyl compounds. During the reaction process, sulfur dioxide anion radical is the key intermediate, which is usually generated from a single electron transfer under suitable conditions. The advantages using sodium dithionite or thiourea dioxide in the sulfonylation reactions include mild conditions and broad substrate scope with excellent functional group compatibility. Further applications by using sodium dithionite and thiourea dioxide in organic transformations will be anticipated.
Reported herein is the first example of heterogeneous palladium catalyzed C(sp3)-H bonds arylation by a transient-ligand-directed strategy. Using supported palladium (metallic state) nanopariticles as catalyst, a wide range of aryl iodides undergo the coupling with various o-methylbenzaldehyde derivatives to assemble a library of highly selective and functionalized o-benzylbenzaldehydes. The stability of the catalyst was easily recovered four runs without significant loss of activity. The XPS analysis of the catalyst before and after reaction indicated that the reaction might be carried out by a catalytic cycle starting with Pd0.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
