derivatives (10), acid (11), esters (12) and amides (13) were synthesized starting from 2. 7-Ethyl- (4b) and 7-propylcamptothecin (4c), acyloxymethyl compounds 6a, 6c and ethyl ester (12b) exhibited higher antitumor activity than 1 against L1210 in mice.
Photoredox-mediated Minisci C–H alkylation of N-heteroarenes using boronic acids and hypervalent iodine
作者:Guo-Xing Li、Christian A. Morales-Rivera、Yaxin Wang、Fang Gao、Gang He、Peng Liu、Gong Chen
DOI:10.1039/c6sc02653b
日期:——
A photoredox-mediated Minisci C–H alkylation reaction of N-heteroarenes with alkyl boronic acids is reported. A broad range of primary and secondary alkyl groups can be efficiently incorporated into various N-heteroarenes using [Ru(bpy)3]Cl2 as photocatalyst and acetoxybenziodoxole as oxidant under mild conditions. The reaction exhibits excellent substrate scope and functional group tolerance, and
A New Strategy To Improve the Metabolic Stability of Lactone: Discovery of (20<i>S</i>,21<i>S</i>)-21-Fluorocamptothecins as Novel, Hydrolytically Stable Topoisomerase I Inhibitors
was validated by the discovery of (20S,21S)-21-fluorocamptothecins as hydrolytically stable topoisomerase Iinhibitors. A highly potent camptothecin derivative, 8l, was successfully identified, which showed excellent in vitro and in vivo antitumor activities and represents a promising lead for the discovery of novel antitumor agents. Interestingly, this study also provided a new structure–activity
(CPT) derivatives bearing with terminal aza-heterocyclic groups were synthesized, and their antitumoractivity was evaluated both in vitro and in vivo. Hydroxyl-amide analogues with morpholin-4-yl displayed excellent antitumoractivity in vitro and efficient inhibition on tumor xenograph model in nude mice. Ester-amide compounds acted less active in vitro cytotoxicity and lower inhibition activity in
A General Organocatalytic System for Electron Donor–Acceptor Complex Photoactivation and Its Use in Radical Processes
作者:Eduardo de Pedro Beato、Davide Spinnato、Wei Zhou、Paolo Melchiorre
DOI:10.1021/jacs.1c05607
日期:2021.8.11
variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions