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Although great success has been achieved in catalytic asymmetric hydroamination of unactivated alkenes using transition metal catalysis and organocatalysis, the development of catalytic desymmetrising hydroamination of such alkenes remains a tough challenge in terms of attaining a high level of stereocontrol over both remote sites and reaction centers at the same time. To address this problem, here we report a highly efficient and practical desymmetrising hydroamination of unactivated alkenes catalysed by chiral Brønsted acids with both high diastereoselectivity and enantioselectivity. This method features a remarkably broad alkene scope, ranging from mono-substituted and gem-/1,2-disubstituted to the challenging tri- and tetra-substituted alkenes, to provide access to a variety of diversely functionalized chiral pyrrolidines bearing two congested tertiary or quaternary stereocenters with excellent efficiency under mild and user-friendly synthetic conditions. The key to success is indirect activation of unactivated alkenes by chiral Brønsted acids via a concerted hydroamination mechanism.

To assess the effectiveness of acupuncture, exercise rehabilitation, and their combination in treating knee osteoarthritis (KOA). Methods: This randomized controlled trial was done on patients with KOA, who were randomly allocated to three groups: acupuncture (AP), exercise rehabilitation (ER), or a combination of acupuncture and exercise rehabilitation (AE). The study lasted 12 weeks with 4 weeks of treatment and 8 weeks of follow-up. The primary outcome was the response rate, which was determined by the percentage of participants who experienced a significant improvement in pain and function by the fourth week. The primary analysis utilized a Z test for proportions in the modified intent-to-treat population, consisting of all randomized participants with at least one post-baseline measurement. Results: Out of the 120 patients initially enrolled in the study, 110 completed the trial and were included in the intention-to-treat analysis. Response rates at week 4 were 65.7% (23 out of 35), 58.3% (21 out of 36), and 83.3% (32 out of 39) in the AP, ER, and AE groups, respectively. The response rate in the AE group was found to be significantly higher than that in the ER group at week 4. No significant differences were observed in the overall response rates between the AP and ER groups, as well as between the AP and AE groups. Conclusion: Our research indicates that both acupuncture and exercise rehabilitation can effectively enhance pain relief, functional improvement, and joint mobility in individuals aged 45 to 70 with moderate to severe chronic KOA. Furthermore, the AE group demonstrated the highest response rate. These beneficial outcomes were sustained for a minimum of 8 weeks post-treatment. The combination of acupuncture and exercise rehabilitation appears to enhance the overall therapeutic efficacy for KOA patients, suggesting a synergistic effect that may be particularly advantageous for those with moderate to severe symptoms. [ABSTRACT FROM AUTHOR]

Currently,the recognition technology targeted at human action in an interior scene is widely used in video content understanding,home-based care,medical care and other fields,and existing researches pay more heed to the modelling of human action,while ignoring the connection between interior scene and human action in videos.With a view to making full use of the relevance between the scene information and the human motion,this paper studies the recognition approaches for human action in an interior scene based on scene-prior knowledge.Yet,the paper proposes scene-prior knowledge inflated 3D ConvNet(SPI3D).Firstly,the ResNet152 network is adopted to extract scene features for scene classification.Then,based on the results,combined with scene-prior knowledge,this paper introduces quantified scene prior knowledge,optimizes the overall objective function by constraining the weights.Additionally,aiming at the problem that most of the existing data sets focus on the characteristics of human action,whereas the scene information remains complex and plain,an interior scene-action database(SADB) is established.It is shown in experimental results,on the SADB,the recognition accuracy rate of SPI3D reaches 87.9%,6% higher than the recognition accuracy of I3D directly.It can be seen that the modelling for the recognition on human action in interior scene is featured by better performance after introducing the prior knowledge of the scene.

As a research hotspot in the field of emotion analysis,Russian multimodal sentiment analysis technology can automatically analyze and identify emotions through rich information such as text,voice and image,which is helpful to timely understand the public opinion hotspots in Russian speaking countries and areas.However,there are only a few multimodal emotion corpora in Russian,which limits the further development of Russian emotion analysis technology.Based on the analysis of the related research and emotion classification methods of multimodal emotion corpus,this paper develops a scientific and complete tagging system,which includes 11 items of information in utterance,space-time and emotion.In the whole process of corpus construction and quality control,this paper follows the principle of emotional subject and emotional continuity,formulates a strong operational annotation specification and constructs a large-scale Russian emotional corpus.Finally,it discusses the application of corpus in the analysis of emotional expression characteristics,the analysis of personality characteristics and the construction of emotion recognition model.

Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive radical species. Here we report a catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical sources, providing a versatile platform to access four types of enantioenriched α-tertiary pyrrolidines bearing β-perfluorobutanyl, trifluoromethyl, difluoroacetyl and even difluoromethyl groups in excellent yields and with excellent enantioselectivity. The key to success is not only the introduction of the CuBr/chiral phosphoric acid dual-catalytic system but also the use of silver carbonate to suppress strong background and side hydroamination reactions caused by a stoichiometric amount of the in situ generated HCl. Broad substrate scope, excellent functional group tolerance and versatile functionalization of the products make this approach very practical and attractive.

In contrast with the well‐established C(sp2)−SCF3 cross‐coupling to forge the Ar−SCF3 bond, the corresponding enantioselective coupling of readily available alkyl electrophiles to forge chiral C(sp3)−SCF3 bond has remained largely unexplored. We herein disclose a copper‐catalyzed enantioselective radical C(sp3)−SCF3 coupling of a range of secondary/tertiary benzyl radicals with the easily available (Me4N)SCF3 reagent. The key to the success lies in the utilization of chiral phosphino‐oxazoline‐derived anionic N,N,P‐ligands through tuning electronic and steric effects for the simultaneous control of the reaction initiation and enantioselectivity. This strategy can successfully realize two types of asymmetric radical reactions, including enantioconvergent C(sp3)−SCF3 cross‐coupling of racemic benzyl halides and three‐component 1,2‐carbotrifluoromethylthiolation of arylated alkenes under mild reaction conditions. It therefore provides a highly flexible platform for the rapid assembly of an array of enantioenriched SCF3‐containing molecules of interest in organic synthesis and medicinal chemistry. [ABSTRACT FROM AUTHOR]

In contrast with the well‐established C(sp2)−SCF3 cross‐coupling to forge the Ar−SCF3 bond, the corresponding enantioselective coupling of readily available alkyl electrophiles to forge chiral C(sp3)−SCF3 bond has remained largely unexplored. We herein disclose a copper‐catalyzed enantioselective radical C(sp3)−SCF3 coupling of a range of secondary/tertiary benzyl radicals with the easily available (Me4N)SCF3 reagent. The key to the success lies in the utilization of chiral phosphino‐oxazoline‐derived anionic N,N,P‐ligands through tuning electronic and steric effects for the simultaneous control of the reaction initiation and enantioselectivity. This strategy can successfully realize two types of asymmetric radical reactions, including enantioconvergent C(sp3)−SCF3 cross‐coupling of racemic benzyl halides and three‐component 1,2‐carbotrifluoromethylthiolation of arylated alkenes under mild reaction conditions. It therefore provides a highly flexible platform for the rapid assembly of an array of enantioenriched SCF3‐containing molecules of interest in organic synthesis and medicinal chemistry. [ABSTRACT FROM AUTHOR]

The enantioconvergent radical Suzuki–Miyaura cross-coupling of racemic alkyl halides represents a powerful approach for the construction of valuable C(sp3)–C bonds. In this regard, the earth-abundant first-row transition metal (Ni, Fe, Co, and Cu) catalyst possesses a good single-electron transfer ability and can easily convert racemic alkyl halides to the prochiral alkyl radicals, providing an ideal solution for enantioconvergence. The utilization of chiral ligands would further facilitate the realization of enantioselective control over the prochiral alkyl radicals. This Perspective will discuss the advances and anticipate further development in this burgeoning field. [ABSTRACT FROM AUTHOR]