Electrocatalytic Cascade Selenylation/Cyclization/Deamination of 2-Hydroxyaryl Enaminones: Synthesis of 3-Selenylated Chromones under Mild Conditions.

Herein, we disclosed a highly efficient pathway toward 3-selenylated chromone derivatives via electrocatalytic cascade selenylation/cyclization/deamination of 2-hydroxyaryl enaminones with diselenides. This method showed mild conditions, easy operation, wide substrate scope, and good functional group tolerance. Furthermore, this electrosynthesis strategy was amendable to scale-up the reaction. Additionally, the preliminary experiments revealed that this reaction probably proceeded via a cation pathway instead of a radical pathway.

Photoionization cross sections measurements of the excited states of lutetium and ytterbium in the near threshold region.

In this work, the threshold photoionization cross sections from the excited states of lutetium and ytterbium atoms were investigated by the laser pump-probe scheme under the condition of saturated resonant excitation. We obtained the resonance enhanced multiphoton ionization spectra of the lutetium and ytterbium atoms of the lanthanide metals in the range of 307.50-312.50 nm and 265.00-269.00 nm, respectively; the photoionization cross sections of the 5d6s(1D)6p(2D05/2) and 5d6s(3D)6p(2P01/2) states of lutetium and the 4f13(2F0)5d6s2(J = 1) states of ytterbium above threshold regions (0.4-1.6 eV) were measured, and measured values ranged from 2.3 ± 0.2 to 17.7 ± 1.5 Mb.

Properties of Gaseous Deprotonated L-Cysteine S-Sulfate Anion [cysS-SO3]-: Intramolecular H-Bond Network, Electron Affinity, Chemically Active Site, and Vibrational Fingerprints.

L-cysteine S-sulfate, Cys-SSO3H, and their derivatives play essential roles in biological chemistry and pharmaceutical synthesis, yet their intrinsic molecular properties have not been studied to date. In this contribution, the deprotonated anion [cysS-SO3]- was introduced in the gas phase by electrospray and characterized by size-selected, cryogenic, negative ion photoelectron spectroscopy. The electron affinity of the [cysS-SO3]• radical was determined to be 4.95 ± 0.10 eV. In combination with theoretical calculations, it was found that the most stable structure of [cysS-SO3]- (S1) is stabilized via three intramolecular hydrogen bonds (HBs); i.e., one O-H⋯⋯N between the -COOH and -NH2 groups, and two N-H⋯⋯O HBs between -NH2 and -SO3, in which the amino group serves as both HB acceptor and donor. In addition, a nearly iso-energetic conformer (S2) with the formation of an O-H⋯⋯N-H⋯⋯O-S chain-type binding motif competes with S1 in the source. The most reactive site of the molecule susceptible for electrophilic attacks is the linkage S atom. Theoretically predicted infrared spectra indicate that O-H and N-H stretching modes are the fingerprint region (2800 to 3600 cm-1) to distinguish different isomers. The obtained information lays out a foundation to better understand the transformation and structure-reactivity correlation of Cys-SSO3H in biologic settings.

The length of stay and inpatient burden in inpatients with different psoriasis subtypes.

Background: Heavy disease burden of psoriasis has been indicated by previous studies. However, the cost of care and length of stay (LOS) in inpatients with different psoriasis subtypes were rarely addressed. This study aimed to investigate the cost of care and LOS in Chinese patients with different psoriasis types and to clarify the independent factors affecting LOS. Methods: We conducted a cross-sectional study by enrolling patients with psoriasis who were hospitalized between 13 Feb 2017 and 29 Mar 2021. Demographic and clinical characteristics of the patients were collected by reviewing their Electronic Medical Records. Multivariate linear regression was used to estimate the associations with adjustments. Results: A total of 310 adult patients with psoriasis were included (mean cost of care: 13.0±22.3 kCNY; mean LOS: 7.9±4.3 days). Statistically significant differences were found among patients with different psoriasis subtypes in LOS (P<0.001) but not in the cost of care (P=0.530). Relative to psoriasis vulgaris, pustular psoriasis (Adjusted coefficient: 2.37, 95% confidence interval (CI): 0.87-3.87) and erythrodermic psoriasis (Adjusted coefficient: 2.92, 95%CI: 1.38-4.47) were significantly associated with an increased LOS. Meanwhile, respiratory tract infections (Adjusted coefficient: 1.60, 95%CI: 0.11-3.10) also significantly increased the LOS. On the contrary, a decreased LOS was found in psoriatic arthritis patients treated with TNF-alpha inhibitors (Adjusted coefficient: -2.21, 95%CI: -4.37 to -0.05). Conclusions: LOS differed significantly among different psoriasis subtypes while the inpatient burden for a single hospitalization was alike. Infection is an important factor associated with a longer LOS. TNF-alpha inhibitors evidently reduced the total hospital stay period for patients with psoriatic arthritis.

Cu-Catalyzed Oxidative Dual Arylation of Active Alkenes: Preparation of Cyanoarylated Oxindoles through Denitrogenation of 3-Aminoindazoles.

A novel and mild Cu-catalyzed oxidative dual arylation of carbon-carbon double bonds in acrylamides with 3-aminoindazoles is proposed for the synthesis of cyanoarylated oxindoles. Notably, 3-aminoindazoles are employed as efficient arylating agents via the cleavage of two C-N bonds. This oxidative dual arylation of active alkenes involves a radical process and undergoes a sequence of 3-aminoindazole oxidation, two-C-N-bond cleavage, cyanoaryl radical addition, and intramolecular cyclization.

Development of a miniature time-of-flight mass spectrometer coupled with an improved substrate-enhanced laser-induced acoustic desorption source (SE-LIAD/TOF-MS).

A novel, compact and sensitive SE-LIAD/TOF-MS has been described. It facilitates fast sample preparation, and a full mass spectrum is acquired efficiently and sensitively. More importantly, it features the detection of non-acidic and non-basic or non-polar species, which is not suitable for determination by ESI and MALDI techniques. In this technique, standard samples, carbazole and melamine, are prepared on a Ti foil with a quartz plate attached to the backside of the Ti foil to perform a laser-induced acoustic desorption experiment (SE-LIAD) coupled to TOF-MS for analysis. Enhanced signals are observed with about 5.6 to 13.8 times higher than that obtained in the standard LIAD method, dependent on different ionization techniques. Compared to the EI spectra, the PI spectra for both species show intact and sharp molecular peaks. The limits of detection (LOD) of melamine were evaluated experimentally in the range from ∼2-6 pg (EI/MS mode) to ∼0.3-0.5 ng (VUV-SPI/MS mode). Thus, the method in this study exhibits rapid qualitative and quantitative analysis with good sensitivity, being free of the complex matrix influences.

Visible Light-Catalyzed Cascade Radical Cyclization of N-Propargylindoles with Acyl Chlorides for the Synthesis of 2-Acyl-9H-pyrrolo[1,2-a]indoles.

A novel and convenient visible light-catalyzed tandem radical cyclization of N-propargylindoles with acyl chlorides for accessing 2-acyl-9H-pyrrolo[1,2-a]indoles is established. This transformation involves sequential addition of the acyl radical to the carbon-carbon triple bond, intramolecular cyclization with the 2-position of indole, and isomerization of the carbon-carbon double bond. The experimental results show that this reaction contains a radical pathway and a radical chain process is not the major pathway for the formation of products.

Synthesis of 2-Acyl-3,4-dihydronaphthalenes by Silver-Promoted Oxidative C-C σ-Bond Acylation/Arylation of Alkylidenecyclopropanes with α-Ketoacids.

A novel and efficient AgNO3-facilitated oxidative C-C σ-bond difunctionalization of alkylidenecyclopropanes with α-ketoacids for preparing 2-acyl-substituted 3,4-dihydronaphthalenes is developed. This radical acylation/arylation transformation proceeds via decarboxylation of the α-ketoacid, acylation of the carbon-carbon double bond, cleavage of the carbon-carbon σ-bond, and cyclization with a connected aromatic ring and offers a mild and facile strategy for acylation/arylation of carbon-carbon σ-bonds with an acyl radical and an aromatic ring to build two new carbon-carbon bonds. This method uses an inexpensive oxidant, features a wide substrate scope, and is operationally simple.

Oxone-Mediated Radical C-C Bond Acetmethylation/Arylation of Methylenecyclopropanes and Vinylcyclopropanes with α-Alkyl Ketones: Facile Access to Oxoalkyl-Substituted 3,4-Dihydronaphthalenes.

An efficient oxone-mediated radical carbon-carbon σ-bond acetmethylation/arylation of methylenecyclopropanes with α-C(sp3)-H bonds of ketones is described for the preparation of 2-(2-oxopropyl)-3,4-dihydronaphthalenes. This acetmethylation/arylation undergoes a series of α-C(sp3)-H bond activation, carbon-carbon double bond acetmethylation, carbon-carbon σ-bond cleavage, and cyclization with intramolecular aromatic ring. The experimental result indicates that the carbon-carbon σ-bond acetmethylation/arylation transformation contains a radical process. The difunctionalization method can also be applied to carbon-carbon σ-bond acetmethylation/arylation of vinylcyclopropanes with ketones. This strategy offers an efficient and convenient method for acetmethylation/arylation of a carbon-carbon σ-bond with a α-carbonyl radical and an aromatic carbon in one pot, building two new carbon-carbon bonds.

Visible-Light-Catalyzed C-C Bond Difunctionalization of Methylenecyclopropanes with Sulfonyl Chlorides for the Synthesis of 3-Sulfonyl-1,2-dihydronaphthalenes.

A novel visible-light-catalyzed sulfonylation/arylation of carbon-carbon σ-bond with sulfonyl chlorides for the synthesis of 3-sulfonylated 1,2-dihydronaphthalenes is developed. This difunctionalization proceeds via a sequence of C═C bond sulfonylation, C-C σ-bond cleavage, and intramolecular cyclization, and the experiment result shows that the C-C σ-bond difunctionalization reaction includes a radical process. This strategy provides a simple and convenient route for difunctionalization of C-C bonds with an aromatic carbon and a sulfonyl radical by one-pot construction of a C-S bond and a new C-C bond.

Visible-light-induced cascade sulfonylation/cyclization of N-propargylindoles with aryldiazonium tetrafluoroborates via the insertion of sulfur dioxide.

A simple and efficient visible-light-catalyzed cascade sulfonylation/cyclization of N-propargylindoles with K2S2O5 and aryldiazonium tetrafluoroborates for the construction of 2-sulfonyl-substituted 9H-pyrrolo[1,2-a]indoles is developed. In this transformation, K2S2O5 as a simple and inexpensive sulfur dioxide source provides sulfur dioxide for accessing sulfonyl radicals. This method features excellent functional group tolerance and offers a convenient route for assembling a new C-C bond and two new C-S bonds in one step.

Visible-light-mediated difunctionalization of vinylcyclopropanes for the synthesis of 1-sulfonylmethyl-3,4-dihydronaphthalenes.

An efficient method for visible-light-mediated sulfonylation/arylation of the C-C σ-bond in vinylcyclopropanes with sulfonyl chlorides to synthesize 1-sulfonylmethyl-substituted 3,4-dihydronaphalenes has been developed. A radical-type pathway has been proved in this transformation. This difunctionalization procedure shows a series of advantages, such as the use of commercially and easily available sulfonyl chlorides, mild conditions, and eco-friendly energy.

Silver-mediated oxidative C-C bond sulfonylation/arylation of methylenecyclopropanes with sodium sulfinates: facile access to 3-sulfonyl-1,2-dihydronaphthalenes.

The novel AgNO3-mediated oxidative sulfonylation/arylation of a C-C σ-bond in methylenecyclopropanes with sodium sulfinates to synthesize various 3-sulfonylated 1,2-dihydronaphthalenes is reported. This sulfonylation/arylation transformation proceeds via a sequence of sulfonylation, C-C σ-bond cleavage and intramolecular cyclization, and the experimental results show that the C-C σ-bond difunctionalization reaction includes a radical process. This strategy provides a simple and convenient route for the difunctionalization of C-C bonds with a phenyl ring and a sulfonyl radical via the one-pot construction of a C-S bond and a new C-C bond.

Oxidative radical ring-opening/cyclization of cyclopropane derivatives.

The ring-opening/cyclization of cyclopropane derivatives has drawn great attention in the past several decades. In this review, recent efforts in the development of oxidative radical ring-opening/cyclization of cyclopropane derivatives, including methylenecyclopropanes, cyclopropyl olefins and cyclopropanols, are described. We hope this review will be of sufficient interest for the scientific community to further advance the application of oxidative radical strategies in the ring-opening/cyclization of cyclopropane derivatives.

Visible-Light-Mediated Ipso-Carboacylation of Alkynes: Synthesis of 3-Acylspiro[4,5]trienones from N-(p-Methoxyaryl)propiolamides and Acyl Chlorides.

A novel visible-light-mediated ipso-carboacylation of N-(p-methoxyaryl)propiolamides with acyl chloride has been established for the synthesis of diverse 3-acylspiro[4,5]trienones with high selectivity and efficiency. This method represents a new difunctionalization of alkynes through cross coupling of the acyl chloride C-Cl bonds with an ipso-aromatic carbon by simultaneously forming two new carbon-carbon bonds and one carbon-oxygen double bond.

Oxidative C-C Bond Functionalization of Methylenecyclopropanes with Aldehydes for the Formation of 2-Acyl-3,4-dihydronaphthalenes.

A new FeCl2- and DTBP (di- tert-butyl peroxide)-promoted oxidative ring-opening and cyclization of methylenecyclopropanes with aldehydes for the synthesis of 2-acyl-3,4-dihydronaphthalenes is presented. This oxidative cyclization reaction proceeds via a radical addition, ring-opening, and cyclization sequence facilitated by a Lewis acid, and it offers a practical and straightforward route for the oxidative cyclization of methylenecyclopropanes with an aromatic carbon and a C(sp2)-H bond by simultaneously forming two new carbon-carbon bonds.

Metal-Free Oxidative C-C Bond Functionalization of Methylenecyclopropanes with Ethers Leading to 2-Substituted 3,4-Dihydronaphthalenes.

A novel metal-free oxidative ring-opening/cyclization of methylenecyclopropanes with ethers was established for the synthesis of diverse 2-substituted 3,4-dihydronaphthalenes with high selectivity and efficiency. This oxidative cyclization is achieved by C(sp3)-H functionalization, ring-opening, and cyclization, and this method represents a new example of methylenecyclopropane oxidative cyclization with an aromatic carbon and a C(sp3)-H bond by simultaneously forming two new carbon-carbon bonds.