Photoinduced decatungstate-catalyzed C(sp3)-H thioetherification by sulfinate salts

Thiols and thioesters play crucial roles in pharmaceuticals, biology, and material science as essential organosulfur compounds. Leveraging readily available and cost-effective inert alkanes through direct thioetherification holds promise for yielding high-value-added products. Herein, we present a photoinduced strategy for sulfur-containing modification of inert alkanes utilizing decatungstate as hydrogen atom transfer reagent, offering a straightforward and practical approach for synthesizing thioethers and thioesters.

Photoelectrochemical oxidative C(sp3)-H borylation of unactivated hydrocarbons

Organoboron compounds are of high significance in organic synthesis due to the unique versatility of boryl substituents to access further modifications. The high demand for the incorporation of boryl moieties into molecular structures has witnessed significant progress, particularly in the C(sp3)-H borylation of hydrocarbons. Taking advantage of special characteristics of photo/electrochemistry, we herein describe the development of an oxidative C(sp3)-H borylation reaction under metal- and oxidant-free conditions, enabled by photoelectrochemical strategy. The reaction exhibits broad substrate scope (>57 examples), and includes the use of simple alkanes, halides, silanes, ketones, esters and nitriles as viable substrates. Notably, unconventional regioselectivity of C(sp3)-H borylation is achieved, with the coupling site of C(sp3)-H borylation selectively located in the distal methyl group. Our method is operationally simple and easily scalable, and offers a feasible approach for the one-step synthesis of high-value organoboron building blocks from simple hydrocarbons, which would provide ample opportunities for drug discovery.

Iron-Catalyzed C(Sp3)-H Borylation, Thiolation, and Sulfinylation Enabled by Photoinduced Ligand-to-Metal Charge Transfer

Catalytic C(sp³)-H functionalization has provided enormous opportunities to construct organic molecules, facilitating the derivatization of complex pharmaceutical compounds. Within this framework, direct hydrogen atom transfer (HAT) photocatalysis becomes an appealing approach to this goal. However, the viable substrates utilized in these protocols are limited, and the site selectivity shows preference to activated and thermodynamically favored C(sp³)-H bonds. Herein, we describe the development of undirected iron-catalyzed C(sp³)-H borylation, thiolation, and sulfinylation reactions enabled by the photoinduced ligand-to-metal charge transfer (LMCT) process. These reactions exhibit remarkably broad substrate scope (>150 examples in total), and most importantly, all of these three reactions show unconventional regioselectivity, with the occurrence of C(sp³)-H borylation, thiolation, and sulfinylation preferentially at the distal methyl position. The procedures are operationally simple and readily scalable and provide access to high-value products from simple hydrocarbons in one step. Mechanistic studies and control experiments indicate that the afforded site selectivity is not only relevant to the HAT species but also largely affected by the use of boron- and sulfone-based radical acceptors.

Iminyl-Radical-Promoted C-C Bond Cleavage/Heck-Like Coupling via Dual Cobaloxime and Photoredox Catalysis

We report herein an unprecedented protocol for radical-olefin coupling of α-imino-oxy acids and alkenes for the synthesis of alkene-containing nitriles via synergistic photoredox and cobaloxime catalysis. With visible-light irradiation, the transformation provides a variety of corresponding alkene-containing nitriles under mild reaction conditions. The C-C bond cleavage/Heck-like coupling reaction could generate E-selective coupling products with excellent chemo- and stereo-selectivity. This iminyl-radical-mediated reaction is external-oxidant-free, exhibits wide functional-group compatibility, and occurs with the extrusion of acetone, H₂, and CO₂.

Amidyl radical-mediated aminodifluoroallylation of alkenes via photoredox catalysis

A practical and redox-neutral method is developed for the synthesis of gem-difluoroalkene-containing N-heterocycles via photoredox catalysis.

Photoredox-neutral alkene aminoarylation for the synthesis of 1,4,5,6-tetrahydropyridazines

A mild and redox-neutral protocol is developed for the synthesis of 1,4,5,6-tetrahydropyridazines via photoredox catalysis.

Visible-Light-Promoted Intramolecular α-Allylation of Aldehydes in the Absence of Sacrificial Hydrogen Acceptors

We report herein an unprecedented protocol for radical cyclization of aldehydes with pendant alkenes via synergistic photoredox, cobaloxime, and amine catalysis. The transformation was achieved in the absence of external oxidants, providing a variety of 5-, 6-, and 7-membered ring products with alkene transposition in satisfactory yields. The reaction exhibits wide functional group compatibility and occurs under mild conditions with extrusion of H₂.

Metal-free iminyl radical-mediated C–C single bond cleavage/functionalization of redox-active oxime esters

By photoactivating Hantzsch ester (HE) to act as an electron donor, we have achieved single-electron reduction of cycloketone oxime esters, thus providing a novel catalyst-free strategy for alkylation, allylation, vinylation and alkynylation.

Ni-Catalyzed deaminative hydroalkylation of internal alkynes

A regioselective cis-hydroalkylation of internal alkynes with readily prepared Katritzky pyridinium salts for the synthesis of tri-substituted alkenes is described. This reaction is the first example of a metal-catalyzed hydroalkylation of an alkyne via C-N bond activation of an amine. The reaction demonstrates broad scope and functional group tolerance, allowing access to desired products with high diversity. Preliminary mechanistic studies indicate that a combination of an SET-initiated radical process and Ni-catalyzed alkylation could engage in the reaction, which makes it possible to bypass the traditional open-shell addition pathway.

Genetic dissection of upland cotton (Gossypium hirsutum) cultivars developed in Hubei Province by mapped SSRs

The genetic diversity of 51 upland cotton cultivars with different parental origins and breeding periods that were developed in Hubei Province was studied on the basis of 237 mapped simple sequence repeat markers covering the cotton genome. A total of 108 polymorphic primer pairs amplified 196 loci; the polymorphism information content range was 0.04 to 0.83, with an average of 0.46. A model-based clustering analysis (STRUCTURE) of the genomic data identified 3 clear subpopulations, and the result was confirmed by principal components analysis. The genetic similarity coefficient among 51 upland cotton cultivars was 0.598 on average, ranging from 0.378 to 0.817. The unweighted pair group method with arithmetic average cluster analysis revealed inconsistencies in other clustering patterns: "Tianmian1" was distinct from the rest of the materials and formed a separate cluster. This study will provide a guide for breeders to develop new cultivars efficiently and to choose parents, and it supports the need to introduce new alleles into the gene pool of the upland cotton breeding program in Hubei Province.

[Detecting effect comparison between MPAIA, DDIA and IHA for screening advanced schistosomiasis]

OBJECTIVE

To evaluate the effects of the magnetic particle antibody immunoassay (MPAIA), dipstick dye immunoassay (DDIA) and indirect hemagglutination assay (IHA), on detecting advanced schistosomiasis.

METHODS

The sera of 224 cases of advanced schistosomiasis were detected by MPAIA, DDIA, and IHA, and the positive rates were compared.

RESULTS

The positive rates of MPAIA, DDIA and IHA, were 67.14%, 14.29% and 16.52%, respectively,the positive coincidence rate of MPAIA is higher than the one of IHA and DDIA.

CONCLUSION

The value of MPAIA is higher than that of DDIA or IHA in screening advanced schistosomiasis.