Conversion of Phenols and Anilines to -Olefins via Oxidation, Wittig Olefination, and Stereoselective Olefin Isomerization.

Development of metal-free conversion of naturally abundant phenols and anilines to the corresponding olefins remains a formidable challenge. The current state of the art relies on the TM-catalyzed Heck coupling of activated phenols (triflates, tosylates, and more) with the olefins. While these advancements are promising, the reaction suffers from branch vs linear selectivity and requires an expensive TM-ligand combination, hazardous organotin reagents, and very high reaction temperature.

Alkoxide-Assisted Stereoselective Functionalization of 1,2-Bis-boronic Esters Under Photoredox Catalysis.

Site-specific functionalization of the secondary C-B bond of 1,2-bis-boronic esters has been proven to be an important method for the generation of 1,2-bis-functionalized compounds in a highly stereoselective manner. We have explored previously unknown secondary selective alkenylation, allylation, alkynylation and addition to aryl vinyl trifluoromethane, which proceeds via a novel reaction mechanism: alkoxide-mediated photoredox activation to generate secondary radicals over the primary one.

Predictive Nomogram and Propensity Score Matching in Neuroendocrine Carcinoma of the Tubular Gastrointestinal Tract: A US Population-Based Clinical Outcome Study.

Neuroendocrine carcinomas (NECs) of the tubular gastrointestinal tract (GI-NECs) are rare and associated with worse clinical outcomes. This population-based study aims to highlight key demographics, clinicopathological factors, and survival outcomes in the US population. Data from 10,387 patients with GI-NECs were extracted from the Surveillance, Epidemiology, and End Result (SEER) database from 2000 to 2020.

One pot conversion of phenols and anilines to aldehydes and ketones exploiting α gem boryl carbanions.

Functional group interconversion is an important asset in organic synthesis. Phenols/anilines being naturally abundant and the carbonyl being the most common in a wide range of bioactive molecules, an efficient conversion is of prime interest. The reported methods require transition metal catalyzed cross coupling which limits its applicability.

SpyGlass DS system-assisted retrieval of proximally migrated pancreatic duct stent in a patient with chronic pancreatitis.

Pancreatic duct (PD) stent migration is among the recognized complications of endoscopic retrograde cholangiopancreatography (ERCP) with PD stent placement. Proximal stent migration poses a challenge for removal due to risks of PD damage, smaller caliber, and possible stricture. Here, we present a case of SpyGlass DS system-assisted PD stent repositioning after failure with traditional tools.

Carbonyl group directed synthesis of 3-boryl-3-substituted alkenyl oxindoles and tetrasubstituted β-borylenones.

Transition metal-free carbonyl directed boron-Wittig reaction of α-bis(boryl)carbanions with the corresponding isatins or with the α-keto esters/amides was achieved to access alkenyl oxindoles in good yield and high stereoselectivity.

Lupus Pancreatitis Masquerading as Pancreatic Cancer: A Rare Clinical Presentation.

Systemic lupus erythematosus (SLE) is an autoimmune multisystemic inflammatory disease. SLE-associated pancreatitis is uncommon, and pancreatic cancer in SLE is very rare. Imaging findings in SLE with pancreatitis can mimic malignancy.

Pemphigus vulgaris presenting with epigastric pain.

Pemphigus vulgaris is an autoimmune mucocutaneous disease with an involvement in gastrointestinal tract especially in oral cavity and esophagus. Ulcers can be the initial presentation even before visible mucosal or cutaneous lesions. The presenting symptoms will be in accordance with the affected organ such as throat pain, hoarseness, dysphagia, odynophagia, or even bleeding.

Dissociable contributions of basolateral amygdala and ventrolateral orbitofrontal cortex to flexible learning under uncertainty.

Reversal learning measures the ability to form flexible associations between choice outcomes with stimuli and actions that precede them. This type of learning is thought to rely on several cortical and subcortical areas, including highly interconnected orbitofrontal cortex (OFC) and basolateral amygdala (BLA), and is often impaired in various neuropsychiatric and substance use disorders. However, unique contributions of these regions to stimulus- and action-based reversal learning have not been systematically compared using a chemogenetic approach and particularly before and after the first reversal that introduces new uncertainty.

1,2-Metallate Rearrangement Using Indole Boronate Species to Access 2,3-Diarylindoles and Indolines.

A transition metal-free multicomponent reaction using lithiated indole, boronic ester, pyridine, and ethyl chloroformate was developed to access C2,C3 bis-arylated indoles, which are present in several marketed drugs and bioactive compounds. One-pot access to unsymmetrical C2,C3-diaryl indole from the parent indole remains a huge synthetic challenge. Our group was able to achieve this goal through a transition metal-free 1,2-metalate rearrangement of the indole boronate complex.

Mechanistic dichotomy in the solvent dependent access to -allylic amines decarboxylative vinylation of amino acids.

The solvent plays an important role in the photophysical properties of donor-acceptor based photocatalysts. The solvent-dependent access to -allylic amines was achieved decarboxylative vinylation of amino acids with vinyl sulfones. Detailed experimental studies have been conducted to understand the role of the solvent in the reactivity and stereoselectivity of the vinylation reactions.

Development of Methods to the Synthesis of β-Boryl Acyls, Imines and Nitriles.

Organoboron compounds are highly important and versatile synthetic intermediates for the preparation of a wide range of organic molecules. Organoboron compounds have drawn significant attention among organic chemists due to their Lewis acidic property, non-toxicity, and commercial availability. Over the last several decades, there has been a substantial development of new organoboron compounds, useful in organic synthesis.

Endoscopic diverticulotomy for Killian-Jamieson diverticulum: mid-term outcome and description of an ultra-short tunnel technique.

Killian-Jamieson Diverticulum (KJD) is a rarer and more recently described upper pharyngeal diverticulum than Zenker's diverticulum (ZD). KJD is more difficult to manage than ZD because it tends to extend lower into the upper mediastinum and the diverticulum neck is in close proximity to the recurrent laryngeal nerve. There is limited literature on KJD management and transcervical surgical diverticulectomy is the mainstay of therapy.

Unique features of stimulus-based probabilistic reversal learning.

Reversal learning paradigms are widely used assays of behavioral flexibility with their probabilistic versions being more amenable to studying integration of reward outcomes over time. Prior research suggests differences between initial and reversal learning, including higher learning rates, a greater need for inhibitory control, and more perseveration after reversals. However, it is not well-understood what aspects of stimulus-based reversal learning are unique to reversals, and whether and how observed differences depend on reward probability.

Synthesis and reactivity of alkynyl boron compounds.

Over the last century, there have been considerable developments in organoboron chemistry due to the stability, non-toxicity, and easy commercial availability of various boronic esters. Several organoboron reagents have emerged and play an increasingly important role in everyday organic synthesis. Among them, alkynyl boron compounds have attracted significant attention due to their easy synthesis and diverse reactivity.

Transition metal-free synthesis of alkyl pinacol boronates.

Alkyl pinacol boronic esters have been routinely used for the synthesis of complex target molecules or high-value chemicals due to their non-toxicity, stability and commercial availability. The synthesis of C-B bonds in the absence of transition metals has gained significant attention due to its added advantages. Numerous methods have been developed for the synthesis of alkyl pinacol boronates without transition metals, which include reactions using organometallic reagents, Lewis acids and bases, photoredox catalysis, and 1,2-metallate rearrangement.

Functionalization of Heterocycles through 1,2-Metallate Rearrangement of Boronate Complexes.

Over the last decade, 1,2-metallate rearrangement of boronate complex has been dominating the literature of organoboron chemistry for the construction of very important C-C and C-boron bonds. Owing to the coordinative unsaturated nature of the boron atom, a nucleophile can attack on boron center for the formation of a boronate complex, which triggers 1,2-migration under electrophilic activation at the α-carbon. Apart from using stochiometric electrophilic activating reagents, several catalytic methods using transition metals in the presence or absence of light have been reported.

Sex-dependent effects of chronic intermittent voluntary alcohol consumption on attentional, not motivational, measures during probabilistic learning and reversal.

Background: Forced alcohol (ethanol, EtOH) exposure has been shown to cause significant impairments on reversal learning, a widely-used assay of cognitive flexibility, specifically on fully-predictive, deterministic versions of this task. However, previous studies have not adequately considered voluntary EtOH consumption and sex effects on probabilistic reversal learning. The present study aimed to fill this gap in the literature.

Transition-Metal-Free Synthesis of Heterobiaryls through 1,2-Migration of Boronate Complex.

The synthesis of a diverse range of heterobiaryls has been achieved by a transition-metal-free sp -sp cross-coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl-heteroaryl boronate complex, which triggered 1,2-migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield.

A novel technique of endoscopic submucosal dissection for circumferential ileocecal valve adenomas with terminal ileum involvement: the "doughnut resection" (with videos).

Background: Ileocecal valve (ICV) lesions are difficult to resect endoscopically and patients are often referred for laparoscopic colectomy. ICV involvement has been shown to be related to technical failure and tumor recurrence after endoscopic mucosal resection (EMR) and represents a challenge for endoscopic submucosal dissection (ESD). Few publications have focused specifically on endoscopic management of ICV lesions.

Silver oxide mediated novel SET oxidative cyclization: stereoselective synthesis of 3-azabicyclo[n.1.0]alkanes.

For the first time, silver oxide catalyzed SET-oxidative cyclization of an α-amidinoester tethered with an alkene, leading to a novel cyclopropane-fused cyclic amidine, has been developed. This efficient method permits easy access to the pharmaceutically important 3-azabicyclo[n.1.

Unusual Presentation of Duodenal Ulcer Presenting with Duodenal Intussusception.

We present a unique case of duodeno-duodenal intussusception from a duodenal bulb ulcer. A 38-year-old man presented with nausea, vomiting, and abdominal pain. Computed tomography showed duodenal intussusception.

No apparent benefit of preemptive sorafenib therapy in liver transplant recipients with advanced hepatocellular carcinoma on explant.

Background: Sorafenib has shown survival benefits in patients with advanced HCC; however, limited data are available on its role in OLT recipients with advanced HCC in the explant.

Aim: Evaluate the role of preemptive sorafenib therapy on HCC recurrence and survival after OLT with advanced HCC on explant pathology.

Methods: We retrospectively reviewed the outcome after OLT of all HCC recipients with advanced HCC in the explant pathology from 04/2006 to 12/2012 based on preemptive treatment with sorafenib.