Leveraging Pyrazolium Ylide Reactivity to Access Indolizine and 1,2-Dihydropyrimidine Derivatives.

N-Heterocyclic ylides are important synthetic precursors to rapidly build molecular complexity. Pyrazolium ylides have largely been unexplored, and we demonstrate their diverse utility in this report. We show that these readily accessible building blocks can be used to construct different heterocyclic skeletons by varying the coupling partner. Indolizines can be formed via an N-deletion type mechanism when reacting pyrazolium salts with electron deficient alkynes. 1,2-Dihydropyrimidines can be formed via a rearrangement mechanism when reacting pyrazolium ylides with isocyanates. These reactions enable access to valuable heteroarenes without the need for transition metal catalysis, high temperatures, or strong bases.

From Elective to Emergent Cholecystectomy: A Single-Center Experience.

BACKGROUND: Symptomatic cholelithiasis is a common disease in which the majority of patients are managed electively. There is an unknown proportion of patients who require emergency surgery for acute cholecystitis in this elective waiting period. Our study aimed to evaluate risk factors for requiring an emergency cholecystectomy during this waiting period. METHODS: This single-center retrospective observational study queried medical records for scheduled elective cholecystectomies from 2017 to 2022. We then evaluated these patients to determine who required emergency intervention via acute cholecystectomy. Patient demographics were analyzed. Patient cohort subgroups were created for patients who waited longer than 60 days and less than 60 days. RESULTS: 1086 patients from 2017 to 2022 were scheduled for an elective cholecystectomy. Of those, 48 required emergency cholecystectomy. Average wait times of those who required emergent cholecystectomy were found to be significantly higher at 60.3 d, compared to 47.3 d for the elective group (P = .03*). Subgroup analysis of patients with >60 d average wait time re-demonstrated significance with 92.1 d and 115.7 d (P = .004) for the elective and emergency subgroups, respectively. >60 d wait time showed increased odds ratio of 1.805 (P = .05) for requiring an emergency cholecystectomy. Logistic regression analysis identified >60 d waiting period (P = .01) and obesity (P = .0001) as predictors of needing emergency surgery. DISCUSSION: Wait time >60 d is associated with an increased risk of emergent cholecystectomy. Obesity was identified as a key risk factor which should be considered for stratifying patients for more urgent surgical intervention.