Zirconium-Catalyzed Synthesis of 6-(Trifluoromethyl)-2H-pyran-2-ones via C-C Bond Cleavage.

A strategy for the annulation reaction of alkynones with ethyl 4,4,4-trifluoro-3-oxobutanoate through C-C bond cleavage is described. The zirconium-catalyzed transformation provides access to a wide range of structurally diverse 6-(trifluoromethyl)-2H-pyran-2-ones in moderate to good yields, utilizing Na2CO3 as a base. Further transformations into trifluoromethylated arene derivatives have been demonstrated as well. Furthermore, plausible reaction pathways are proposed by conducting various control experiments and isolating a ß-diketone intermediate (X-ray) containing an intramolecular hydrogen bond.

In Vivo Profiling with 18F-YJH08 Reveals Diverse Tissue Patterns of Antagonist/Glucocorticoid Receptor Interactions.

Demonstrating target engagement in vivo is an important milestone in drug development, both to establish on target, on tissue interactions but also to identify potentially undesirable off tissue binding. The glucocorticoid receptor (GR) is a long-studied yet vexing drug target that has recently re-emerged as a potential druggable driver of many solid tumor types including breast and prostate cancer, and several antagonists are currently in early phase clinical trials. Since GR is also ubiquitously expressed in normal tissues, understanding antagonist/GR interactions in normal tissues and tumor is crucial to defining a therapeutic index. Herein, we demonstrate that the GR radioligand 18F-YJH08 can map drug/GR engagement in vivo. Profiling target engagement in vivo showed that the GR antagonists RU486 (mifepristone) and CORT125281 engaged GR in fewer normal tissues compared to ORIC-101 or the agonist dexamethasone. Furthermore, 18F-YJH08 detected GR in human prostate cancer tumor models and measured receptor binding by RU486. In summary, these data show for the first time that antagonist/GR interactions can be measured in vivo with 18F-YJH08, a finding with clinical relevance as GR antagonists and 11C-YJH08 are currently in clinical trials.

Synthesis of 2,3-Bis(trifluoromethylseleno) Indoles through an Oxidative Copper-Mediated Domino Reaction.

An oxidative copper-mediated double trifluoromethylselenolation of terminal 2-alkynylanilines using [(bpy)CuSeCF3]2 is reported, providing a moderately efficient and convenient approach to 2,3-bis(trifluoromethylseleno)indoles. Mechanistic studies show that a cascade sequence of oxidation, trifluoromethylselenolation, 5-endo-dig cyclization, and elimination is involved in this transformation.

An aerobic copper-mediated domino process for the synthesis of 3-(trifluoromethylseleno)indoles.

An aerobic copper-mediated domino reaction for the synthesis of 3-(trifluoromethylseleno)indoles by trifluoromethylselenolation of N-Ts 2-alkynylaniline with [(bpy)CuSeCF3]2 is reported. This reaction proceeds through sequential oxidation, alkyne coordination, and deprotonation followed by reductive elimination. This mild and robust method is highly functional group tolerant and provides straightforward access to 3-(trifluoromethylseleno)indoles in moderate to good yields.

Synthesis of 2-trifluoromethyl thiazoles via [3 + 2] cycloaddition of pyridinium 1,4-zwitterionic thiolates with CF3CN.

2,2,2-Trifluoroacetaldehyde O-(aryl)oxime was employed for the [3 + 2] cycloaddition of pyridinium 1,4-zwitterionic thiolates for the synthesis of 2-trifluoromethyl 4,5-disubstituted thiazoles. The reaction works well with various substituted pyridinium 1,4-zwitterionic thiolates in moderate to good yields. The synthetic potential of the obtained 2-trifluoromethyl 4,5-disubstituted thiazoles was demonstrated.

Collaborative Activation of Trifluoroacetyl Diazoester by a Lewis Acid and Base for the Synthesis of Polysubstituted 4-Trifluoromethylpyrazoles.

A Lewis acid- and base-co-mediated cyclization of trifluoroacetyl diazoester and ketones is developed. Cooperative functioning of the Lewis acid and Lewis base with trifluoroacetyl diazoester results in increased electrophilicity of terminal nitrogen atoms. The reaction affords polysubstituted 4-trifluoromethyl pyrazoles in moderate to excellent yields.

Trifluoroacetic Anhydride Promoted Copper(I)-Catalyzed Interrupted Click Reaction: From 1,2,3-Triazoles to 3-Trifluoromethyl-Substituted 1,2,4-Triazinones.

A copper(I)-catalyzed interrupted click reaction in the presence of trifluoroacetic anhydride has been developed, wherein an N-trifluoroacetyl group is used to accelerate the ring-opening of the putative 5-copper(I) triazolide intermediate. Under the optimized reaction conditions, a broad range of azides and alkynes were found to participate in this transformation, thus affording 3-trifluoromethyl-substituted 1,2,4-triazinones in moderate to excellent yields. The reaction has proven to be compatible with a variety of electron-withdrawing and electron-donating groups, halogens, and nitrogen- and sulfur-containing heterocycles, as well as pharmaceutically relevant molecules.

Synthesis of Vinyl Trifluoromethyl Thioethers via Copper-Mediated Trifluoromethylthiolation of Vinyl Bromides.

A copper-mediated trifluoromethylthiolation of vinyl bromides has been developed. This method provides ready access to vinyl trifluoromethyl thioethers in good to high yields from simple, inexpensive starting materials. A broad substrate scope is achieved, and the reaction is compatible with various functional groups, including cyano, nitro, trifluoromethyl, alkoxy, amino, halide, and heterocyclic groups.

Well-defined copper(i) fluoroalkoxide complexes for trifluoroethoxylation of aryl and heteroaryl bromides.

Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated.

Efficient C(sp3alkyl)-SCF3 bond formations via copper-mediated trifluoromethylthiolation of alkyl halides.

A general and convenient copper-mediated trifluoromethylthiolation of primary and secondary alkyl halides was described. Variation of the solvent, additives and time allowed optimization of the reaction. A wide range of alkyl halides were explored to give a set of alkyl trifluoromethyl thioethers in moderate to excellent yields. A variety of functional groups, including ethers, thioether, esters, nitriles, amides, and ketal groups, were well tolerated in the electrophilic partner.

One-Pot Assembly of 2-Trifluoromethyl Benzothiazole and Benzoselenazole via Copper-Mediated Three-Component Cascade Reaction.

A domino one-pot synthesis of 2-(trifluoromethyl) benzothiazole via copper-mediated three-component cascade reaction starting from the easily accessible starting materials such as o-iodoanilines, methyl trifluoropyruvate, and elemental sulfur is reported. The present strategy displayed a comprehensive substrate scope and good functional group tolerance and enabled access to a variety of substituted 2-(trifluoromethyl) benzothiazoles. A 2-(trifluoromethyl) benzoselenazole has also been synthesized utilizing this reaction methodology.

Research on factors influencing the academic entrepreneurial ability of teachers in the digital age: Evidence from China.

In the contemporary digital economy, economic development increasingly relies on the innovation and dissemination of knowledge. Academic entrepreneurship, as a direct channel for knowledge dissemination into the marketplace, is significantly influenced by digital technology. Consequently, how to improve academic entrepreneurial ability has become a hot research topic. This study is grounded in the theory of reciprocal determinism within the context of the digital economy. We use the "2019 China Digital Economy Development Index White Paper" and collect data from 1843 survey questionnaires in China to conduct empirical research with a ridge regression model. It primarily focuses on the following individual factors and social environmental factors on academic entrepreneurial ability of teachers (AEAT): digital economy (DE), organizational support (OS), policy environment (PE), and personal learning growth (PLG). First, the findings show that the DE, OS, PE, and PLG have a significant positive impact on improving AEAT. Second, the results also indicate that social environmental factors relative to personal factors will have a greater impact. Finally, this study not only presents the first attempt to establish a connection between DE and AEAT but also holds significant managerial implications for enhancing AEAT within the context of the DE. Despite the increasing body of literature on academic entrepreneurship, the research domain pertaining specifically to AEAT remains fragmented and lacks comprehensive theoretical development. There is a pressing need for more systematic and thorough investigations to unveil the black box of factors influencing AEAT in the context of the DE.

2,2,2-Trifluoroacetaldehyde O-(Aryl)oxime: A Precursor of Trifluoroacetonitrile.

The preparation of 2,2,2-trifluoroacetaldehyde O-(aryl)oxime, a previously inaccessible precursor of trifluoroacetonitrile, via reaction of hydroxylamine and trifluoroacetaldehyde hydrate is reported. This precursor released CF3CN in quantitative yield under mildly basic conditions. The precursor was successfully used in the synthesis of trifluoromethylated oxadiazoles. The facile, cost-effective, scalable, and recyclable procedure makes these trifluoroacetonitrile precursors generally applicable.

Regioselective synthesis of 3-trifluoromethyl 1,2,4-triazoles via photocycloaddition of sydnone with CF3CN.

A general and regioselective synthesis of 3-trifluoromethyl 1,2,4-triazoles has been achieved through photocycloaddition of sydnone with trifluoroacetonitrile. This method employed trifluoroacetaldehyde O-(aryl)oxime as the CF3CN precursor and tolerated various functional groups to furnish 3-trifluoromethyl 1,2,4-triazole products in moderate to good yields. Mechanistic experiments revealed an energy transfer from photocatalyst 4-CzIPN to the sydnone substrates.

Silicon Distribution-Induced Actuation Film with Bidirectional Bending Deformation and Versatile Bionic Applications.

As an important branch of intelligent materials, the research and development of stimulus-responsive flexible intelligent actuation materials is of great significance to promote the industrialization of intelligent materials. In this study, the asymmetric PVA-co-PE/silicon nanoparticle (PPSN) composite films and PVA-co-PE/silicon sol (PPSS) composite film with different silicon distributions were prepared by a simple spraying method. The silicon nanoparticle layer in the PPSN composite film was similar to the sand-like water-absorbing layer, which can quickly absorb water and permeate it into the interior region, leading to the hygroscopic expansion behavior on one side of the nanofiber film. Then, the PPSN composite film would quickly bend and deform to the silicon nanoparticle side. However, in the PPSS composite film, due to the excellent hygroscopicity and swelling characteristics of the silica sol layer, the composite film can be rapidly deformed to the PVA-co-PE nanofiber film side under moisture stimulation. The above results subvert the traditional asymmetric actuation film, which mainly depends on the hydrophilicity difference to determine the hygroscopic responsiveness and deformation direction, and ignore that the swelling degree is the main factor determining the bending direction of actuator. In addition, both the composite films can quickly respond to moisture stimulation (<1 s) and produce large-scale bending deformation (180°). Furthermore, due to the excellent interface adhesion formed by the continuity structure in the PPSS composite film, it has better actuation stability than the PPSN composite film. The excellent actuation characteristics and different bending directions of the PPSN and PPSS composite films make it a great application prospect in the field of bionics in the future.

The Impact of Entrepreneurship Competitions on Entrepreneurial Competence of Chinese College Students.

Entrepreneurship competitions are an important way to implement entrepreneurship education in universities and the main way for many students improve their entrepreneurial competence. To clarify the mechanism of the role of entrepreneurship competition on the entrepreneurial competence of university students, based on data from a sample of 170,764 university students from 31 provinces in China, this study constructs a moderated mediation model that focuses on the mediating role of entrepreneurial spirit (ES) in entrepreneurial competition (ECompetition) and entrepreneurial competence (ECompetence) and the moderating role of entrepreneurial practice (EP). The results showed that ECompetition found to have a significant positive predictive effect on ECompetence. ES plays a mediating role in the relationship between ECompetition and competence. The direct predictive effect of ECompetition on ECompetence and the mediating effect of ES on their relationship is moderated by EP. The results provide a new perspective on the impact of entrepreneurship competition on college students' entrepreneurial competence and expands the experiential learning theory in entrepreneurship education.

Relationship Between Entrepreneurship Education Curriculum and Agricultural Students' Satisfaction in China.

Developing agriculture is an important way to get rid of poverty and boost economic development. Entrepreneurship, especially entrepreneurship education, is considered to be an important contributor to the realization of the above objectives. Entrepreneurship education has received more and more attention. Improving the entrepreneurial willingness and skills of agricultural students is of great significance to the economic and social development of developing countries. In order to explore the relationship between entrepreneurship education curricula and satisfaction, especially the agricultural students, we conducted a questionnaire survey in 35 universities across the country between 2018 and 2019 to evaluate the entrepreneurship education of agricultural students in Chinese universities. And 1223 valid questionnaires with 7 interviews were obtained. Furthermore, we used the structural equation model to empirically analyze the questionnaire data and found that entrepreneurship practice plays a part in the mediating effect between entrepreneurship curriculum and satisfaction with entrepreneurship education. This paper expands literature on entrepreneurship education and has certain reference significance for training a large number of agricultural entrepreneurial talents the practice of entrepreneurship education in other developing countries.

How to Improve Entrepreneurship Education in "Double High-Level Plan" Higher Vocational Colleges in China.

Entrepreneurship education complements vocational education in helping students develop their career prospects. This empirical study comprehensively analyzed sample data of 13,885 students from 40 "Double High-level Plan" higher vocational colleges in China using robust standard error regression analysis and other methods. The results showed that Entrepreneurship Practice (EP), Entrepreneurship Curriculum (EC), and Integration of Entrepreneurship Education and Professional Education (IEEPE) have a significant positive effect on Entrepreneurship Education Performance (EEP), with EP being the most important factor. Furthermore, ascribed factors (gender, household registration, only child or not, whether parents have entrepreneurial experience) and self-achieved factors (double high-level type, school area, subject major, whether to accept social entrepreneurship education) were found to affect students' perception of investment in entrepreneurship education. The study summarizes the existing problems of entrepreneurship education in "Double High-level Plan" higher vocational colleges and proposes four suggestions: pursue the integrated development of entrepreneurship education and "Double High-level" construction, advance both theoretical education and practical education, promote digital reform of the "three teaches" (teachers, teaching materials, and teaching methods), and develop entrepreneurship education in a comprehensive and balanced manner. This has certain theoretical and practical significance for the improvement of entrepreneurship education in other developing countries.

Entrepreneurship Education, Psychological Cognition, and Entrepreneurship Activities: An Analysis Based on a Fuzzy-Set Qualitative Comparative Analysis.

At present, research in the field of college students' entrepreneurship has proliferated, but these studies tend to analyze the net benefits of various factors on entrepreneurial activities, which are affected by the configuration effects of multiple factors; hence, it remains unclear whether entrepreneurial education can make graduates more efficient to started their own companies. To fill this gap in the literature, drawing on general systems theory and using fuzzy-set qualitative comparative analysis (fsQCA), we take 1,87,914 undergraduate and junior college students from 1,231 colleges and universities in China as a sample to explore the relationships among the five conditions in the entrepreneurship education environment and cognitive level (i.e., the quality of staff, subject curriculum, entrepreneurial competition, intentions, and opportunity identifications) and entrepreneurial activities. The fsQCA results show that none of these factors are sufficient for entrepreneurial activity. In contrast, three combinations of the five conditions (i.e., co-creation type, competition-oriented environment, and entrepreneurship education that fits under the guidance of entrepreneurial intention) can produce high entrepreneurial activity, as well as substitution and complementarity among the various elements within the configuration. These results show that the combined effect of the five conditions is more conducive to the entrepreneurial activities of college students. Finally, after a discussion of the study's findings, theoretical, and practical contributions are analyzed with regard to the field of entrepreneurship in Chinese colleges, and alternative options indicate that college students are more likely to become entrepreneurs in the future.

The Role of Entrepreneurship Policy in College Students' Entrepreneurial Intention: The Intermediary Role of Entrepreneurial Practice and Entrepreneurial Spirit.

Entrepreneurship is a sustainable development tool that supports the alleviation of poverty and unemployment. Focusing on the promotion of entrepreneurial intention (EI) under the background of entrepreneurship education (EE), this study used a structural equation model to examine the role of entrepreneurship policy (EPo), entrepreneurial practice (EPr), and entrepreneurial spirit (ES) on the EI of 384 college students from 22 universities in Guangdong Province. The test results show that there are significant positive correlations between EPo and EI; EPo and EPr; EPo and ES; and EPr and EI. They also support the hypothesis that EPr enhances the positive effect that EPo has on EI. This study puts forth measures to improve EI and makes contributions to future research on EE.