The direct CH arylation of (hetero)arenes has gradually emerged as a viable alternative for traditional cross-coupling reactions. In this context, the application of focused microwave irradiation has opened new avenues by ameliorating the major bottlenecks like low yields, prolonged reaction times, and/or high catalyst loadings. For more details see the Minireview by E. Van der Eycken et al. on page 1158 ff.
The synthesis of the newly marketed anticancer drug vinflunine classically starts from the biomimetic coupling of catharanthine and vindoline, two monomeric units extracted from the leaves of the Madagascar periwinkle, followed by superacidic fluorination to afford vinflunine. An alternative approach for the synthesis of vinflunine (see dashed arrows) is presented by E. Doris et al. in their Communication on page 1170 ff. This strategy is based on the direct fluorination of the catharanthine skeleton under mild conditions and biomimetic coupling of the resulting difluorocatharanthine with the vindoline unit. However, unexpected products arose from the biomimetic coupling step.
The sensitive fluorimetric detection of G-quadruplex DNA in biological samples is a challenging task, requiring fluorescent probes with high selectivity over duplex DNA. In their Full Paper on page 1214 ff., M.-P. Teulade-Fichou et al. show that asymmetric (2,4-disubstituted) distyrylpyridinium dyes selectively bind to quadruplex DNA structures over double-stranded DNA and their fluorescence is selectively increased in the presence of quadruplex DNAs. The analogous symmetric dye displays a strong binding preference for double-stranded DNA and its fluorimetric response is increased equally by quadruplex and duplex DNA.