Visible-Light-Mediated Activation of Remote C(sp)-H Bonds by Carbon-Centered Biradical via Intramolecular 1,5- or 1,6-Hydrogen Atom Transfer.

In this study, we introduce a novel intramolecular hydrogen atom transfer (HAT) reaction that efficiently yields azetidine, oxetane, and indoline derivatives through a mechanism resembling the carbon analogue of the Norrish-Yang reaction. This process is facilitated by excited triplet-state carbon-centered biradicals, enabling the 1,5-HAT reaction by suppressing the critical 1,4-biradical intermediates from undergoing the Norrish Type II cleavage reaction, and pioneering unprecedented 1,6-HAT reactions initiated by excited triplet-state alkenes. We demonstrate the synthetic utility and compatibility of this method across various functional groups, validated through scope evaluation, large-scale synthesis, and derivatization.

A comparative study of clinicopathological and imaging features of HBV-negative and HBV-positive intrahepatic cholangiocarcinoma patients with different pathologic differentiation degrees.

Hepatitis B is a risk factor for the development of intrahepatic cholangiocarcinoma. The prognosis of HBV-related ICC remains to be further investigated. To investigate the clinical, pathological and imaging features of intrahepatic cholangiocarcinoma of hepatitis B virus-positive and -negative patients.

Nomogram based on clinical and preoperative CT features for predicting the early recurrence of combined hepatocellular-cholangiocarcinoma: a multicenter study.

Purpose: To establish and validate a multiparameter prediction model for early recurrence after radical resection in patients diagnosed with combined hepatocellular-cholangiocarcinoma (cHCC-CC).

Materials And Methods: This study reviewed the clinical characteristics and preoperative CT images of 143 cHCC-CC patients who underwent radical resection from three institutions. A total of 110 patients from institution 1 were randomly divided into training set (n = 78) and testing set (n = 32) in the ratio of 7-3.

Visible-light-induced dual catalysis for -α C(sp)-H amination and alkenylation of -alkyl benzamides.

The amination and alkenylation of the C(sp)-H bond at the -α position of secondary benzamides were both realized in this work by using -hydroxyphthalimide (NHPI) imidate esters as substrates under a dual catalysis involving a photoredox catalyst and hydrogen atom transfer (HAT) catalyst. The developed methods significantly extended the scope of applications of the -α position C(sp)-H bond functionalization with regard to secondary -alkylamides. More importantly, new reaction models in photoredox catalysis have been established.

Visible-light-induced indole synthesis intramolecular C-N bond formation: desulfonylative C(sp)-H functionalization.

Despite significant advances made on the synthesis of indole derivatives through photochemical strategies during the past several years, the requirement of equivalent amounts of oxidants, bases or other additional additives has limited their practical applications in the synthesis of natural products and pharmaceuticals as environment-friendly processes. Herein, we report LED visible-light-induced redox neutral desulfonylative C(sp)-H functionalization for the synthesis of -substituted indoles with a broad scope through γ-fragmentation under mild conditions in the absence of any additional additive. The reaction mechanism paradigm has been investigated on the basis of deuterium labeling experiments, kinetic analysis, Hammett plotting analysis and DFT calculations.

Selective C(sp)-H bond functionalization of olefins visible-light-induced photoredox-quinuclidine dual catalysis.

The site selective C(sp)-H bond functionalization of olefins has been achieved through a visible-light-induced photoredox-quinuclidine dual catalysis upon merging the quinuclidinium radical cation addition to alkene strategy and the distal heteroaryl -migration strategy. This synthetic protocol features a simple operation with readily available starting materials in good step-economy to access alkenylheteroaromatic products in moderate to good yields under mild conditions. A plausible cascade catalytic reaction mechanism is also proposed.