Copper-Catalyzed Cascade Multicomponent Reaction of Azides, Alkynes, and Selenium: Synthesis of Ditriazolyl Diselenides.

A copper-catalyzed cascade multicomponent reaction for synthesizing ditriazolyl diselenides from azides, terminal alkynes, and elemental selenium has been developed. The present reaction features utilizing readily available and stable reagents, high atom-economy, and mild reaction conditions. A possible mechanism is proposed.

[Structure-activity relationship of annonaceous acetogenins against multidrug resistant human hepatic carcinoma cell line SMMC-7721/ADR].

The present research was launched to investigate the effects of 12 annonaceous acetogenins (ACGs) on human hepatic carcinoma cell line SMMC-7721/ADR, and to find out their structure-activity relationship. SMMC-7721/ADR cells were treated with 12 ACGs including annosquamin A(1)，annosquamin B(2)，annotemoyin-1(3)，uvariamicin Ⅱ(4)，annosquacin D(5)，annosquacin B(6)，isodesacetyluvaricin(7)，uvarigrandin A(8)，squamostatin D(9)，squamostatin E(10)，squamostatin A(11)，and 12,15-cis-squamostatin A(12) for 24 h, and the different expression of the target gene NDUFV2 were detected by quantitative real-time PCR. All the tested compounds made the expression of the target gene NDUFV2 decreased on human hepatic carcinoma cell line SMMC-7721/ADR, of which the bistetrahydrofuran ACGs showed the best activity,which the non-adjacent bistetrahydrofuran ACGs displayed the worst activity.The ACGs with the reducing number of carbons between γ-unsaturated lactone and the close tetrahydrofuran (THF) ring are more potent. For bistetrahydrofuran ACGs with the same nucleus skeleton,they would be more active as more hydroxyls on aliphatic chain, which for the non-adjacent bistetrahydrofuran ACGs with less hydroxyls on aliphatic chain that would be more active. ACGs with 3 hydroxyls on aliphatic chain would be more active. ACGs with threo configuration are more active than erythro configurotion, and the compounds with cis THF ring seem to be superior to those of trans THF ring. Furthermore, the ACGs with the reducing number of carbons between terminal methyl and the close tetrahydrofuran (THF) ring are more potent.

Oxidative Dehydrogenative Coupling of Thiols with Alkanes for the Synthesis of Sulfoxides.

An oxidative dehydrogenative coupling of thiols with alkanes via direct C(sp3)-H bond functionalization to form a new C-S bond and S═O double bond was developed. The present reaction features the use of readily available reagents and high step- and atom-efficiency, thus providing an efficient access to sulfoxides. A possible mechanism is proposed.