Design of a Bilateral Disulfurating Reagent for Unsymmetrical Polysulfidation

In this study, we designed a bilateral disulfurating reagent via S−S motif “snip and stitch” processes, allowing diverse functional groups to be bridged via S−S bonds. The reagent is readily synthesized in high yield using a one-step reaction from easily available starting materials and is air-stable. With this reagent, diverse electrophiles including inactivated alkyl Cl/Br/I/OMs and benzyl chloride were sequentially installed on either side of the S−S motif. Natural products, agrochemicals, and pharmaceuticals can be successively cross-linked with S−S bonds. Notably, the disulfurating reagent can be used in cyclic disulfide synthesis. At last, some desired products of this work showed good antibacterial activities, which could be employed as novel candidates to control plant pathogenic bacteria.     

Group 14 Elements Hetero-Difunctionalizations via Nickel-Catalyzed Electroreductive Cross-Coupling

The difunctionalization of unsaturated bonds plays a vital role in the enrichment of molecular complexity. While various catalytic methods for alkene and alkyne difunctionalization have been developed in recent years, hetero-functionalization the introduction of two different atoms has been less explored. This is mainly due to the challenges associated with achieving high chemo-, regio-, and stereoselectivity, especially when adding two similar atoms from the same group across unsaturated bonds. In this study, we describe a nickel-catalyzed, three-component reductive protocol for group 14 element hetero-difunctionalization of 1,3-enynes using electrochemistry. This new method is mild, selective, and general, allowing for the silyl-, germanyl-, and stannyl-alkylation of enynes. Various chlorosilanes as well as chlorogermans, and chlorostannanes can be successfully used in combination with aryl/alkyl-substituted 1,3-enynes and primary, secondary, and tertiary alkyl bromides in the electroreductive coupling.