From Quaternary Carbon to Tertiary C(sp3)-Si and C(sp3)-Ge Bonds: Decyanative Coupling of Malononitriles with Chlorosilanes and Chlorogermanes Enabled by Ni/Ti Dual Catalysis.

Transition-metal-catalyzed C-Si/Ge cross-coupling offers promising avenues for the synthesis of organosilanes/organogermanes, yet it is fraught with long-standing challenges. A Ni/Ti-catalyzed strategy is reported here, allowing the use of disubstituted malononitriles as tertiary C(sp3) coupling partners to couple with chlorosilanes and chlorogermanes, respectively. This method enables the catalytic cleavage of the C(sp3)-CN bond of the quaternary carbon followed by the formation of C(sp3)-Si/C(sp3)-Ge bonds from ubiquitously available starting materials. The efficiency and generality are showcased by a broad scope for both of the coupling partners, therefore holding the potential to synthesize structurally diverse quaternary organosilanes and organogermanes that were difficult to access previously.

[Influences of human beta-defensin 1 on the replication and expression of HPV18 in Hela cell].

OBJECTIVE: Investigate the influences of human beta-defensinl (hbetaD1) on the replication and expression of HPV18 in Hela cell. METHODS: Gene transfection: mediated by Fugen HD, hbetaD1/psectag plasmid was transfected to Hela cell [hbetaD1/psectag : liposome complexes (hbetaD1/psectag : lip)group], and control groups [psectag : liposome complexes(psectag : lip) group and blank group) were also established. After transfection, the expression of the target gene in Hela cell was investigated by the method of immunocytochemistry. 48 h and 72 h after the transfection, the change of the copy number of HPV18 DNA in Hela cell was investigated respectively by the quantitative fluorescent PCR method, and the change of the HPV18 E6 mRNA in Hela cell was evaluated by the semiquantitative RT-PCR. RESULTS: 48 h and 72 h after the transfection of hbetaD1/psectag plasmid to Hela cell, hbetaD1 was expressed in both of the two groups, and the latter showed a tendency of stronger expression. Compared with the control groups, the copy number of HPV18 DNA in Hela cell in the hbetaD1/psectag : lip group increased at 48 h and decreased at 72 h after the transfection, but the change was not statistically significant. 48 h after the transfection, compared with the control groups, the expression of HPV18 E6 mRNA in Hela cell in the hbetaD1/psectag : lip group changed a little; and 72 h after the transfection, the expression level of HPV18 E6 mRNA decreased significantly (P < 0.05). CONCLUSION: hbetaD1 displayed an inhibitory effect to the expression of HPV18 mRNA in Hela cell in a concentration-dependent pattern, but no significant effect on the duplication of HPV18 DNA.