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A facile approach to densely functionalized cyclopropanes is described. The reaction proceeds under mild conditions via the directed nucleopalladation of non-conjugated alkenes with readily available pronucleophiles and gives excellent yields and good anti-selectivity using I2 and TBHP as oxidants. Pronucleophiles bearing a diverse collection electron-withdrawing groups, including–CN, –CO2R, –COR, –SO2Ph, -CONHR and –NO2, are well tolerated. Internal alkenes, which are generally challenging substrates in other cyclopropanation methods, provide excellent yields and good diastereoselectivity in this methodology, allowing for controlled access to cyclopropanes substituted at all three C-atoms.

A cascade oxazole-benzannulation for the synthesis of naphtho[2,3

Eighteen hybrid compounds between 8-bromo-2-fluoro-isocryptolepine (4) and 1,2,3-triazole were synthesized via azide rearrangement-annulation reaction. Compound 4 underwent regioselective N-propargylation and click reaction to form 8-bromo-2-fluoro-isocryptolepine-triazole hybrids 11 which were evaluated for cytotoxic activity. Compound 11 c containing 1-anisyltriazole was the most effective in inhibiting HepG2, HuCCA-1 and A549 cell lines (IC50 values of 1.65-3.07 μM) while compounds 11 a (1-phenyltriazole), 11 j (1-para-CF3 -benzyltriazole) and 11 l (1-meta-Cl-benzyltriazole) were potent inhibitors of HuCCA-1, HepG2 and A549 cell lines, respectively. Moreover, 11 l showed the lowest cytotoxicity to normal human kidney cell line. Compounds 11 c and 11 l provided improvement of cytotoxic activity over 4. Compounds 4, 11 c and 11 l were selected to investigate their mechanisms of action. The results showed that 4 could induce G2/M cell cycle arrest and was involved in the upregulation of p53 and p21 proteins. However, the mechanisms of growth inhibition by 11 c and 11 l were associated with G0/G1 cell cycle arrest and mediated by induction of oxidative stress.

1,1-Disubstituted vinyl triflates are synthesized by direct hydrotriflation of terminal alkynes employing a combination of TfOH and TMSN3 in DCM at room temperature. Interestingly, under these cond...

1,1-Disubstituted vinyl triflates are synthesized by direct hydrotriflation of terminal alkynes employing a combination of TfOH and TMSN

This study reported the discovery of novel compounds containing five-membered ring fused quinoline core structures as anticancer and antimalarial agents. Two libraries containing these core structures, neocryptolepines and carbocycle-fused quinolines, were prepared and evaluated. Compound 3h was found to be much more potent than other analogs against cancer cell lines with high selectivity. Meanwhile, carbocycle-fused quinolines 5h and 5s showed moderate anticancer properties but much less cytotoxicity to normal cell than doxorubicin. In addition, compound 3h also showed much lower cytotoxic against human normal kidney cell line compared to doxorubicin standard. However, only compounds 3s and 3p provided acceptable results for antimalarial activities.