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This document discusses the challenges and methods for constructing fluorinated quaternary stereogenic centers in organic molecules, which are important in pharmaceuticals. The authors present a Pd-catalyzed allylic C–H alkylation method using an α-fluoroester for the construction of a C–F quaternary stereogenic center. They found that using a chiral phosphoramidite-palladium catalyst and 2,5-diphenylhydroquinone as an oxidant resulted in high yields and selectivities. The researchers also explored the substrate scope and proposed a plausible reaction mechanism. Overall, this study provides an efficient method for synthesizing fluorinated quaternary stereogenic centers. [Extracted from the article]

Background and study aims: Gastrointestinal endoscopy procedures, such as endoscopic retrograde cholangiopancreatography (ERCP), endoscopic submucosal dissection (ESD), and colonoscopy are widely used for the diagnosis or treatment of digestive diseases. Perforation is a rare but potentially lethal complication. Large perforations usually require immediate endoscopic or surgical repair. Endoscopic closure using a nylon loop pouch suture is usually performed with a double-channel endoscope. This paper describes the endoscopic closure of large procedure-related perforations using a single-channel endoscope. Patients and methods: A total of 10 patients with large perforations (2.5-4.0 cm), which occurred during ERCP, ESD, or colonoscopy, were treated using the single-channel endoscope technique. Results: All perforations were successfully closed using a nylon loop pouch suture through the single- channel endoscope. No surgery or further endoscopic intervention was required. Conclusions: Nylon loop pouch suture through a single-channel endoscope was easy to perform and was feasible for the closure of large gastrointestinal perforations. [ABSTRACT FROM AUTHOR]

The article presents a case study of 71-year old man with abdominal pain, jaundice, and fever. It states that the man was diagnosed with duodenal perforation and a single-channel endoscope with titanium clips and nylon loop was performed to him. Furthermore, it mentions that the operation was successful and the method may reduced the potential of hospitalization expenses.