查看更多>>摘要：A convenient photo-dehalogenation of a-haloketones was developed under irradiation with a purple LED. This simple method does not require any catalyst and water could act as the sole additive, affording efficiently the dehalogenated products with different substituents at room temperature in air atmosphere. Mechanistic study indicated that the ether solvent is also the photoreductant for the reaction, and facile a-deuteration of the ketone product could be achieved when deuterated solvent is used.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：An unprecedented method for the palladium-catalyzed disilylation of 2-bromoarylferrocenes with hexamethyldisilane has been developed. The catalytic cycle is initiated by oxidative addition of 2-bromoarylferrocenes to Pd(0), followed by C-H activation to form a reactive five-membered C,C-palladacycle. By using this protocol, a variety of disilylated ferrocene compounds were obtained in moderate to good yields. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Sarglafuran A (1), a new [4 + 2] type lindenane sesquiterpene dimer with an unique furan ring moiety, and a pair of new [2 + 2] type dimeric lindenane epimers, sarglalactones N and O (2 and 3), were isolated from the leaves of Sarcandra glabra. Their structures were elucidated by comprehensive spectroscopic analyses, and the absolute configurations of these compounds were determined by single crystal X-ray diffraction or CD exciton chirality method. In addition, a possible biosynthetic pathway of the unique furan ring moiety in 1 had been proposed. Their cytotoxicity against MCF-7 and MDA-MB-231, together with the inhibitory activity against nitric oxide (NO) production of LPS-induced RAW264.7 macrophages were evaluated.
查看更多>>摘要：Recent advances in selective C-H functionalization have resulted in powerful strategies for the synthesis of important target molecules from petroleum-derived hydrocarbons. In particular, alkylarenes such as toluene and xylenes are abundant feedstock chemicals that are emerging as useful substrates in C-C and C-X bond forming reactions. We review benzylic C-H functionalization of alkylarenes for the synthesis of amines. We focus on the direct coupling of alkylarenes and imines through two distinct modes of activation: heterolytic and homolytic cleavage of benzylic C-H bonds.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：An organophotocatalytic ring opening/remote trifluoromethylselenolation of cycloalkanols is reported. This reaction proceeds the radical ring-opening in a photocatalytic system without metal catalysis under mild conditions, followed by the formation of the remote C(sp3)-SeCF3 bond in the presence of PhSO2SeCF3. The reaction brings out highly reactive to prepare trifluoromethylselenolated carbonyl compounds, suitable for a variety of aryl cyclic alcohols, while compatible with different ring systems with high yield, including 26 examples, the highest isolated yield of 93%. (c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：Carbonyl compounds with a tertiary stereocenter at the a-position are an important class of building blocks in organic synthesis. However, efficient and enantioselective synthesis of this type of compounds are nontrivial. Photochemical deracemization reactions have emerged as a powerful tool towards this end. In this Digest, three recent studies are highlighted to demonstrate the great potential of this strategy and stimulate further development in this area. (C) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：We report a light-gated, catalytic protocol for hydroboration of terminal alkynes based on a bench-stable cobalt(I) hydride complex which undergoes ligand photodissociation with visible light. The products are obtained in good yields and with excellent E-selectivity. (c) 2022 Elsevier Ltd. All rights reserved.
Sansom, Geraud N.Semken, JessicaKelso, Michael J.Richardson, Christopher...
5页
查看更多>>摘要：A new low temperature route to pyrrolo[1,2-a]quinolines bearing ester groups in the 5-position is reported. The reaction mechanism was found to depend on the reaction temperature. At low temperatures it is proposed the reaction proceeds though an addition-intramolecular SNAr-elimination pathway. This method should find wider use as it avoids high boiling point solvents and affords compatibility with thermosensitive substrates.(c) 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A mild photocatalytic C-H bond selective oxidation mediated by metal-free photocatalyst 2-Methylanthraquinone was reported. Glass microchannel reactor can enhance the absorption of photon energy and oxygen by the reaction mixture, so as to greatly improve the reaction efficiency of photocatalytic reaction in glass microchannel reactor. This reaction method can quickly oxidize alkyl aromatics into corresponding oxidation products to obtain aromatic ketones in high yield. CO 2022 Elsevier Ltd. All rights reserved.
查看更多>>摘要：A new monoterpenoid indole alkaloid, arboduridine (1), characterized by a hexacyclic cage skeleton, incorporating cyclohexane, piperidine, and bridged-fused pyrrolidine-tetrahydrofuran moieties, was isolated from a Malayan Kopsia species. The structure of the alkaloid was determined based on analysis of the NMR and MS data, while the absolute configuration was established by ECD measurements in conjunction with DFT calculations. A possible biogenetic pathway from a pericine precursor is presented. (c) 2022 Elsevier Ltd. All rights reserved.
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