RESUMEN
Catalytic C(sp3)-H functionalization has afforded great opportunities to prepare organic substances, facilitating the derivatization of complex drugs and natural molecules. This letter describes an efficient and practical protocol for lanthanum-catalyzed continuous epoxy-ring opening and oxidative dehydrogenative lactonization under visible-light irradiation. Notably, the lanthanum catalyst also acts as a photocatalyst while acting as a Lewis acid in this reaction; therefore, no additional photocatalyst is required. We can conveniently prepare a series of diverse isochromanones with oxygen-containing spirocyclic structural units under a balloon-oxygen atmosphere at room temperature. Mechanistic studies and control experiments reveal that the in situ-generated lanthanum bromide should be crucial in the reaction.
RESUMEN
Direct functionalization of inert C(sp3)-H bonds is an attractive synthetic technology for the preparation of pharmaceutically significant compounds in modern synthetic organic chemistry. In this work, we report a new method for the synthesis of functionalized benzocoumarins through the strategy of activation of multiple C-H bonds on 2-aryl toluenes under visible-light-enabled photoredox conditions. This method has the advantages of high functional group compatibility, mild reaction conditions, and effectively avoiding the use of strong oxidants and precious metal catalysts. Detailed mechanistic investigations, including spectroscopic and electrochemical studies, support the reaction's mechanistic course.
RESUMEN
BACKGROUND: Liver resection is recommended for T2 gallbladder cancer, but the optimal hepatectomy strategy remains controversial. We aimed to assess the safety and effectiveness of segment IVb and V resection versus wedge resection in patients with T2 gallbladder cancer. METHODS: This is a retrospective multicenter propensity score-matched study in China. Overall survival, disease-free survival, perioperative complications, and hospital length of stay were used to evaluate safety and effectiveness. RESULTS: There are a total of 512 patients. 112 of 117 patients undergoing segment IVb and V resection were matched to 112 patients undergoing wedge resection. After matching, segment IVb and V resection demonstrated no statistical difference in overall survival (hazard ratio, 0.970 [0.639-1.474]; P = .886), but significance in disease-free survival (hazard ratio, 0.708 [0.506-0.991]; P = .040). Patients with incidental gallbladder cancer (hazard ratio, 0.390 [0.180-0.846]; P = .019), stage T2b (hazard ratio, 0.515 [0.302-0.878]; P = .016), and negative lymph nodes status (hazard ratio, 0.627 [0.406-0.991]; P = .043) were associated with improved disease-free survival after segment IVb and V resection, but not in wedge resection. However, perioperative complications occurred more frequently after segment IVb and V resection (28.5% vs 9.1%, P < .001) along with the longer hospital length of stay (17.3 vs 10.2 days, P < .001). Notably, patients with jaundice (odds ratio, 4.053 [1.361-12.23]; P = .013), undergoing laparoscopic resection (odds ratio, 2.387 [1.059-4.484]; P = .028) or surgeon performing per the first 10 segment IVb and V resections (odds ratio, 2.697 [1.035-6.998]; P = .041), were the independent risk factors for perioperative complications in the segment IVb and V resection group. CONCLUSION: T2 gallbladder cancer patients undergoing segment IVb and V resection rather than wedge resection have an improved disease-free survival, especially for incidental gallbladder cancer or hepatic-sided (T2b) gallbladder cancer. However, high rates of perioperative complications and longer hospital length of stay after segment IVb and V resection indicated that surgeons must rely on their own surgical skills and the patient profile to decide the optimal hepatectomy strategy.
