Cobalt-Catalyzed Enantioselective Hydroamination of Arylalkenes with Secondary Amines.

Catalytic asymmetric hydroamination of alkenes with Lewis basic amines is of great interest but remains a challenge in synthetic chemistry. Here, we developed a Co-catalyzed asymmetric hydroamination of arylalkenes directly using commercially accessible secondary amines. This process enables the efficient access to valuable α-chiral tertiary amines in good to excellent yields and enantioselectivities. Mechanistic studies suggest that the reaction includes a CoH-mediated hydrogen atom transfer (MHAT) with arylalkenes, followed by a pivotal catalyst controlled SN 2-like pathway between in situ generated electrophilic cationic alkylcobalt(IV) species and free amines. This radical-polar crossover strategy not only provides a straightforward and alternative approach for the synthesis of enantioenriched α-tertiary amines, but also underpins the substantial opportunities in developing asymmetric radical functionalization of alkenes with various free nucleophiles in oxidative MHAT catalysis.

Cobalt-Catalyzed Asymmetric Alkylation of (Hetero)Arenes with Styrenes.

An efficient and general intermolecular Cobalt(II)-catalyzed asymmetric alkylation of styrenes with (hetero)arenes including indoles, thiophene and electron rich arenes has been developed, providing straightforward access to enantioenriched alkyl(hetero)arenes with high enantioselectivity. Mechanistic studies suggest that the reaction underwent a CoH-mediated hydrogen atom transfer (HAT) with alkenes, followed by a pivotal catalyst-controlled SN 2-like pathway between in situ generated organocobalt(IV) species and aromatic nucleophiles. This is the first CoH-catalyzed asymmetric hydrofunctionalization using carbon nucleophiles, providing a new strategy for asymmetric Friedel-Crafts type alkylation.

Copper-Catalyzed Cope-Type Hydroamination of Nonactivated Olefins toward Cyclic Nitrones: Scope, Mechanism, and Enantioselective Process Development.

The catalytic synthesis of cyclic nitrones, an important type of functional molecules for both synthetic chemistry and related fields, remains underdeveloped. Herein we report the copper-catalyzed Cope-type hydroamination of oximes with pendant nonactivated olefins, which enables facile access to a series of five- and six-membered cyclic nitrones under mild conditions. In this study, heterocycle-tethered oximes were employed in the Cope-type hydroamination reaction for the first time. High enantioselectivity was achieved for carbon-tethered γ,δ-vinyl oximes to afford enantioenriched five-membered cyclic nitrones. The results of preliminary mechanistic studies indicate a mononuclear catalytic species and a unified catalytic pathway over a large temperature range.

Risk factors and prognosis of interstitial lung disease for primary Sjögren syndrome patients: A retrospective case‒control study.

OBJECTIVE: To determine the prevalence, clinical features, risk factors, and prognosis of interstitial lung disease (ILD) in patients with primary Sjogren's syndrome (pSS). METHODS: Data from 274 pSS patients from August 2013 to August 2022 were reviewed. The clinical features of pSS with ILD were revealed. Logistic regression was used to determine risk factors for ILD in pSS patients. Survival analysis and Cox regression were used to analyse the prognosis and prognostic factors of pSS patients. RESULTS: In pSS patients, the prevalence of ILD was 22.3% (61/274). The pSS patients with ILD were characterized by a late onset and long disease course, with a nonspecific interstitial pneumonia (NSIP) pattern as the predominant high-resolution computed tomography (HRCT) finding. Logistic regression results indicated that an age over 50 years old (OR 4.786, 95% CI 1.602-14.299; P = 0.005), purpuric rash (OR 4.695, 95% CI 1.537-14.339; P = 0.007), AMA-M2 antibody positivity (OR 2.582, 95% CI 1.166-5.722; P = 0.019), and diabetes (OR 2.514, 95% CI 1.025-6.167; P = 0.044) were risk factors for ILD in pSS patients. Cox regression results showed that advanced age (HR 1.240, 95% CI 1.088-1.413; P = 0.001) and cancer history (HR 8.411, 95% CI 1.771-39.934; P = 0.007) were risk factors for pSS patient survival. CONCLUSION: This study showed that pSS patients with ILD tended to have a late onset and long course of pSS. An age over 50 years, purpuric rash, AMA-M2 antibody positivity, and diabetes were risk factors for ILD in pSS patients. Advanced age and cancer history were prognostic factors in pSS patients. Key Points • This study showed that pSS patients with ILD tended to have a late-onset and lengthy course of pSS, with the NSIP pattern as the predominant lung image. • The risk factors for ILD in pSS patients determined in this study were an age over 50 years, purpuric rash, AMA-M2 antibody positivity, and diabetes. • The prognostic risk factors for pSS patients were advanced age and cancer history.

CoH-catalyzed radical hydroalkylation of alkenes with 1,3-dicarbonyls.

Metal-hydride hydrogen atom transfer (MHAT) catalysis has emerged as a useful reaction platform for alkene hydrofunctionalization with high chemoselectivity and predictable branched selectivity. However, MHAT-mediated hydrofunctionalization involves carbon-carbon bond formation still confined to carbon electrophiles. Here, we describe a mild, general, scalable, and functional group tolerant CoH-catalyzed intermolecular hydroalkylation of alkenes with 1,3-dicarbonyls. This kind of CoH-catalyzed coupling of alkenes with carbon nucleophiles represents an important complement to the arsenal of MHAT-initiated hydrofunctionalization of alkenes.

Retraction: CoH-catalyzed radical hydroalkylation of alkenes with 1,3-dicarbonyls.

Retraction of 'CoH-catalyzed radical hydroalkylation of alkenes with 1,3-dicarbonyls' by Meihui Guan et al., Chem. Commun., 2022, 58, 5265-5268, https://doi.org/10.1039/D2CC01382G.