Copper-catalyzed defluorinative arylboration of vinylarenes with polyfluoroarenes.

An unprecedented but challenging defluorinative arylboration has been achieved. Enabled by a copper catalyst, an interesting procedure on defluorinative arylboration of styrenes has been established. With polyfluoroarenes as the substrates, this methodology offers flexible and facile access to provide a diverse assortment of products under mild reaction conditions. In addition, by using a chiral phosphine ligand, an enantioselective defluorinative arylboration was also realized, affording a set of chiral products with unprecedented levels of enantioselectivity.

Comparing bariatric surgery and medical therapy for obese adolescents with type 2 diabetes.

BACKGROUND: Mounting evidence in recent years has demonstrated that the number of obese adolescents has continued to rise. Obese adolescents are more likely to be diagnosed with type 2 diabetes, which causes additional harm. This study aimed to compare the clinical outcomes of bariatric surgery and medical treatment. METHODS: We conducted a multicenter, nonrandomized, retrospective study on 202 obese adolescents with type 2 diabetes who received surgery or medical treatment in three hospitals from 2017 to 2019. We analyzed the effects of surgery and medical treatment in terms of weight loss, glycemic control and the remission of type 2 diabetes. Propensity score matching was conducted to balance the confounding factors. RESULTS: Among the 202 adolescents, 109 adolescents underwent surgery, and the remaining 93 adolescents received nonsurgical treatment. Both in the entire cohort and in the propensity-score matching cohort, the mean body mass index (BMI) and total weight in the surgery group notably decreased. Similarly, the effect of surgery on glycemic control (with respect to HBG, HbA1c, HOMA-IR) was superior to that of medical treatment. In the surgery group, the remission rate of diabetes was 76.1% in the entire cohort and 80.5% in the matched group, which was significantly higher than that in the control group (6.5% and 5.7%, respectively). In addition, LRYGB had better effects on weight loss and glycemic control than LSG. CONCLUSION: Bariatric surgery is more effective in the control of weight loss and type 2 diabetes than medical treatment. The effects between different types of bariatric surgeries remain to be further investigated, and longer follow-up times are needed.

Primary closure combined with C-tube drainage through cystic duct after laparoscopic common bile duct exploration is safe and feasible for patients.

Objective: Biliary duct management is of great significance after laparoscopic cholecystectomy (LC) combined with laparoscopic common bile duct exploration (LCBDE) in the treatment of cholecystolithiasis accompanied with common bile duct (CBD) stones. This study is to evaluate the safety and effectiveness of primary closure with C-tube drainage through cystic duct after LC + LCBDE. Methods: Through a retrospective study, 290 patients who underwent LC + LCBDE in our hospital from January 2019 to April 2022 were enrolled and divided into 2 groups. 143 patients underwent primary closure with C-tube drainage through cystic duct (C-tube group) and the other 147 patients underwent traditional T-tube drainage (T-tube group). Personal information, perioperative examinations, surgical results, and follow-up results were collected and analyzed. Results: There were no significant differences in the average age, gender, the mean of CBD diameters and the rate of comorbidities (acute cholecystitis, obstructive jaundice, acute pancreatitis and acute cholangitis) between the two groups (P > 0.05). Hospital stay, postoperative hospital stay were significantly shorter in the C-tube group than T-tube group (P < 0.05). In addition, the average time of placing and removal the drainage tubes was significantly less than those of the T-tube group (P < 0.05). This study also showed significant differences in the incidence of postoperative abdominal infection and soft tissue infection in the two groups (P < 0.05). There were no significant differences in the incidence of postoperative complications including cholangitis, bile duct stenosis, mortality in two groups. There were also no significant differences between the two groups of the recurrence of CBD stones, reoperation and readmition in 30 days during the median follow-up of 6 months. Conclusions: Compared with T tube drainage, patients with C-tube drainage after LC + LCBDE with primary closure of cystic duct recovered faster and had fewer complications. C-tube drainage is a safe and feasible treatment option for patients with cholecystolithiasis and choledocholithiasis.

Copper-Catalyzed 1,2-Dicarbonylative Cyclization of Alkenes with Alkyl Bromides via Radical Cascade Process.

Herein, we developed a new procedure on 1,2-dicarbonylative cyclization of 4-aryl-1-butenes with alkyl bromides. Using simple copper catalyst, two molecules of carbon monoxide were introduced into the double bond with the formation of four new C-C bonds and a new ring. Various α-tetralones and 2,3-dihydroquinolin-4-ones were formed in moderate to good yields.

Enantioselective palladium-catalyzed C(sp2)-C(sp2) σ bond activation of cyclopropenones by merging desymmetrization and (3 + 2) spiroannulation with cyclic 1,3-diketones.

Catalytic asymmetric variants for functional group transformations based on carbon-carbon bond activation still remain elusive. Herein we present an unprecedented palladium-catalyzed (3 + 2) spiro-annulation merging C(sp2)-C(sp2) σ bond activation and click desymmetrization to form synthetically versatile and value-added oxaspiro products. The operationally straightforward and enantioselective palladium-catalyzed atom-economic annulation process exploits a TADDOL-derived bulky P-ligand bearing a large cavity to control enantioselective spiro-annulation that converts cyclopropenones and cyclic 1,3-diketones into chiral oxaspiro cyclopentenone-lactone scaffolds with good diastereo- and enantio-selectivity. The click-like reaction is a successful methodology with a facile construction of two vicinal carbon quaternary stereocenters and can be used to deliver additional stereocenters during late-state functionalization for the synthesis of highly functionalized or more complex molecules.

Stereospecific Si-C coupling and remote control of axial chirality by enantioselective palladium-catalyzed hydrosilylation of maleimides.

Hydrosilylation of unsaturated carbon-carbon bonds with hydrosilanes is a very important process to access organosilicon compounds and ranks as one of the most fundamental reactions in organic chemistry. However, catalytic asymmetric hydrosilylation of activated alkenes and internal alkenes has proven elusive, due to competing reduction of carbon-carbon double bond or isomerization processes. Herein, we report a highly enantioselective Si-C coupling by hydrosilylation of carbonyl-activated alkenes using a palladium catalyst with a chiral TADDOL-derived phosphoramidite ligand, which inhibits O-hydrosilylation/olefin reduction. The stereospecific Si-C coupling/hydrosilylation of maleimides affords a series of silyl succinimides with up to 99% yield, >99:1 diastereoselectivity and >99:1 enantioselectivity. The high degree of stereoselectivity exerts remote control of axial chirality, leading to functionalized, axially chiral succinimides which are versatile building blocks. The product utility is highlighted by the enantioselective construction of N-heterocycles bearing up to three stereocenters.

Controllable Si-C Bond Activation Enables Stereocontrol in the Palladium-Catalyzed [4+2] Annulation of Cyclopropenes with Benzosilacyclobutanes.

A novel and unusual palladium-catalyzed [4+2] annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si-C(sp2 ) bond activation in synergy with ring expansion/insertion of cyclopropenes to form new C(sp2 )-C(sp3 ) and Si-C(sp3 ) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo[4.1.0]heptanes, were formed in good yields with excellent diastereoselectivity under mild conditions. An asymmetric version of the reaction with a chiral phosphoramidite ligand furnished a variety of chiral bicyclic silaheterocycle derivatives with good enantioselectivity (up to 95.5:4.5 er). Owing to the mild reaction conditions, the good stereoselectivity profile, and the ready availability of the functionalized precursors, this process constitutes a useful and straightforward strategy for the synthesis of densely functionalized silacycles.

Prognostic value of miRNA-181a/b in colorectal cancer: a meta-analysis.

AIMS: miR-181a and miR-181b have been investigated as prognostic biomarkers of colorectal cancer (CRC). However, there is controversy about the role of miR-181a and miR-181b in predicting CRC prognosis. Therefore, we performed this meta-analysis to evaluate prognostic values of miR-181a and miR-181b in CRC patients. MATERIALS & METHODS: Studies were systemically searched from publications and analyzed, and 999 CRC cases in nine studies were examined in this meta-analysis. RESULTS: Hazard ratio for overall survival of high miR-181a and miR-181b expression in CRC was 1.65. More prominent predictive effects were observed in black people, miR-181b group and small-sample-size group. CONCLUSION: High levels of miR-181a and miR-181b predict poor overall survival in CRC patients. miR-181a and miR-181b are promising biomarkers for CRC prognosis.

Triptycene: no homoconjugation effect for extending optical properties of π-conjugated oligomers.

1,5- and 1,8-bis(bifluorenyl)anthracene were synthesized and converted to their corresponding bis(bifluorenyl)triptycenes and bis(bifluorenyl)-9,10-dihydroanthracenes. Analysis of their optical properties shows no feature of extended conjugation in the triptycene pair. The electronic spectra of the triptycene and dihydroanthracene pairs are in fact superimposable. There is definite evidence that triptycene displays zero homoconjugation effect.