Diastereoselective Generation of C2-Azlactonized 2H-Chromenes via Brønsted Acid-Catalyzed Oxo-Cyclization of Propargyl Alcohols.

A new Brønsted acid-catalyzed oxo-cyclization of propargyl alcohols with azlactones to synthesize C2-azlactonized 2H-chromenes has been established that uses 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BiNPO4H) as the catalyst and gives excellent diastereoselectivities (≥19:1 dr) in most cases. This protocol has a high compatibility with various substituents of substrates, offering a catalytic and useful entry to the fabrication of the synthetically important C2-functionalized 2H-chromene scaffold.

Ligand-Free Pd-Catalyzed Synthesis of 3-Allylbenzofurans by Merging Decarboxylative Allylation and Nucleophilic Cyclization.

A new single Pd-catalyzed decarboxylative allylation-nucleophilic cyclization relay is reported by using α-alkynyl arylols and vinylethylene carbonates (or vinyl carbamates), and a wide range of 3-allyl benzofurans with generally good yields were stereoselectively synthesized under mild conditions, among which the complete stereoselectivity of some cases was also observed. Notably, the present catalysts can tolerate air conditions without any ligand, additive, or base, opening new avenues to build up oxa-heterocycle frameworks through catalytic difunctionalization of internal alkynes.

Synthesis of Diastereoenriched 1-Indanones via Double-Base Cooperatively Promoted 1,4-Oxo-Migration/Cyclization of ß-Alkynyl Ketones.

A double-base copromoted 1,4-oxo-migration/cyclization cascade of ß-alkynyl ketones was reported, enabling to form a range of functionalized 1-indanones with moderate to good yields and high diastereoselectivity in the presence of t-BuOK as a Brønsted base and N,N'-dimethylethanediamine (DMEDA) as a Lewis base. Some of these 1-indanones were successfully transformed into 2-haloethyl benzoates with one all-carbon quaternary stereocenter by 1,2-dichloroethane (DCE) or 1,2-dibromoethane (DBE) as both a reactant and a reaction media. This method also features high atomic utilization (100%), high diastereoselectivity, and mild reaction conditions.

Completely Stereoselective Synthesis of Sulfonated 1,3-Dihydroisobenzofurans via Radical Multicomponent Reactions.

Two types of new oxidant-free radical multicomponent reactions of ß-alkynyl ketones, aryldiazonium salts, and DABCO·(SO2)2 (DABSO) were established, leading to the tunable generation of two class of sulfonated 1,3-dihydroisobenzofurans with moderate to good yields and complete stereoselectivity under the mild conditions. The radical-induced scission/recombination of the C(sp3)-C(sp3) bond enabled direct 1,8-halosulfonylation of ß-alkynyl ketones, giving 1,3-dimethylene-substituted (1Z,3Z)-1,3-dihydroisobenzofurans with substituent diversity by p-nitrobenzyl bromide (PNBB) or p-nitrobenzyl chloride (PNBC) as the halo source. Fine-tuning substituents to strong electron-withdrawing ones, such as nitro, cyano, and trifluoromethyl, linked to aryldiazonium tetrafluoroborates allowed a different annulation/1,5-azosulfonylation process to access sulfonated (Z)-1,3-dihydroisobenzofurans with one quaternary carbon-amino functionality.

MiR-205-5p promotes lung cancer progression and is valuable for the diagnosis of lung cancer.

BACKGROUND: MicroRNAs (miRNAs) function as potential diagnostic biomarkers in various cancers. This study aimed to evaluate the roles of miR-205-5p in lung cancer progression and diagnosis. MATERIALS AND METHODS: MiR-205-5p was detected by quantitative real-time PCR. The effect of miR-205-5p on cell proliferation and metastasis was estimated by MTT and flow cytometry. The expression of TP53INP1 and related genes was analyzed by immunoblotting. The diagnostic value of miR-205-5p was analyzed using receiver operating characteristic (ROC) curve analysis, sensitivity, and specificity. RESULTS: The miR-205-5p was increased in lung cancer tissues. MiR-205-5p mimics were promoted but its inhibitor suppressed cell proliferation and metastasis compared with control treatment in vitro and in vivo. By regulating the 3' untranslated region, miR-205-5p could negatively regulate TP53INP1 expression, which further inhibited the expression of RB1 and P21, but increased that of cyclinD1. Moreover, the serum miR-205-5p levels of patients with lung cancer were significantly higher than those of normal controls, and they were correlated with patients' gender, drinking status, and clinical stage. The area under the ROC curve of serum miR-205-5p in the diagnosis of non-small-cell lung cancer was 0.8250, respectively. The finding supported its possession of high diagnostic efficiency for lung cancer. CONCLUSIONS: MiR-205-5p promoted lung cancer cell proliferation and metastasis by negatively regulating the novel target TP53INP1, which further affected the expression of P21, RB1, and cyclin D1. Serum miR-205-5p is a novel and valuable biomarker for lung cancer diagnosis.

Recent Advances in Radical-Enabled Bicyclization and Annulation/1,n-Bifunctionalization Reactions.

Over the past few years, the development of new radical reactions has gained considerable momentum. Most such radical transformations heavily depend on the in situ generation of reactive radical species, initiated by oxidants, metal salts, visible-light photocatalysis, or electrocatalysis. In this context, numerous radical-enabled bicyclization and annulation/1,n-bifunctionalization reactions have been developed, thereby providing efficient synthetic strategies for the assembly of functionalized cyclic rings that contain both heterocyclic and isocyclic skeletons. In this Focus Review, we highlight recent progress in this rapidly growing area by presenting a series of catalytic oxidative reactions, along with their reaction mechanisms and applications.

Recent advances in radical transformations of internal alkynes.

Over the past years, impressive progress has been made on the development of the chemoselective and direct formation of carbon-carbon and carbon-heteroatom bonds involving internal alkynes under catalytic oxidative systems. These transformations heavily rely on the in situ generation of reactive radical intermediates that are initiated by oxidants, visible light photocatalysis, or electrocatalysis and so on. Numerous chemically and biomedically important building blocks have been synthesized, and will continue to be obtained by taking advantage of the radical transformation of internal alkynes in the following years. In this review, we highlight the recent progress in this rapidly growing area by presenting a series of catalytic oxidative reactions, mechanisms and applications which have appeared in the most recent literature.

Psychophysical evaluation of auditory signals in passenger vehicles.

Twenty-one experienced drivers were recruited for the evaluation of sounds of four functions (horn, indicator, door open warning, and parking sensor) made by 11 car brand names. Each participant was required to evaluate all of the above sound signals by a pair-comparison test. After the comparison test, each participant was shown his/her pair-comparison result and was asked to comment on their preference and appropriateness of a sound. The physical properties and interview data were compared and summarized to propose design recommendations. Our results indicate that complex tones and a fundamental frequency around 450 Hz were most preferred for horns while for indicators the preferred sounds had a higher dominant frequency [corrected].To reduce monotony, the indicators with double clicks and an OFF time interval of between 330 and 400 ms between two clicks were most preferred. Regarding door warning sounds, the waveform starting with a higher intensity then fading towards zero intensity is most preferred while for parking sensors, sounds beginning with a longer OFF time (about 500 ms) and having 3 or 4 distinctive tempo variations were most preferred. The relationship between pleasurability and pitch, loudness, and the tempo of sound signals basically followed an inverted-U function. Sound designers should avoid using very extreme parameter values when generating sound for a given function.

MR imaging of the spine at 3.0T with T2-weighted IDEAL fast recovery fast spin-echo technique.

OBJECTIVE: To compare the iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method with a fat-saturated T2-weighted (T2W) fast recovery fast spin-echo (FRFSE) imaging of the spine. MATERIALS AND METHODS: Images acquired at 3.0 Tesla (T) in 35 patients with different spine lesions using fat-saturated T2W FRFSE imaging were compared with T2W IDEAL FRFSE images. Signal-to-noise ratio (SNR)-efficiencies measurements were made in the vertebral bodies and spinal cord in the mid-sagittal plane or nearest to the mid-sagittal plane. Images were scored with the consensus of two experienced radiologists on a four-point grading scale for fat suppression and overall image quality. Statistical analysis of SNR-efficiency, fat suppression and image quality scores was performed with a paired Student's t test and Wilcoxon's signed rank test. RESULTS: Signal-to-noise ratio-efficiency for both vertebral body and spinal cord was higher with T2W IDEAL FRFSE imaging (p < 0.05) than with T2W FRFSE imaging. T2W IDEAL FRFSE demonstrated superior fat suppression (p < 0.01) and image quality (p < 0.01) compared to fat-saturated T2W FRFSE. CONCLUSION: As compared with fat-saturated T2W FRFSE, IDEAL can provide a higher image quality, higher SNR-efficiency, and consistent, robust and uniform fat suppression. T2W IDEAL FRFSE is a promising technique for MR imaging of the spine at 3.0T.