Sulfur is an essential element because it exists widely in proteins. The disulfide bond is an important moiety in many different types of significant organic molecules. A new approach for oxidant- and catalyst-free S-H/S-H cross-coupling, with hydrogen evolution, to construct unsymmetrical disulfides was developed. Under the conditions of an undivided cell at room temperature, a series of unsymmetrical disulfides were prepared with up to 87 % yield from the direct coupling of an aryl mercaptan and alkyl mercaptan. Gram-scale synthesis also highlights the synthetic utility of this electrochemical strategy.

Sulfur is an essential element because it exists widely in proteins.The disulfide bond is an important moiety in many different types of significant organic molecules.An ew approach for oxidant-and catalyst-free S À H/S À Hc rosscoupling,with hydrogen evolution, to construct unsymmetrical disulfides was developed. Under the conditions of an undivided cell at room temperature,aseries of unsymmetrical disulfides were prepared with up to 87 %yield from the direct coupling of an aryl mercaptan and alkylm ercaptan. Gramscale synthesis also highlights the synthetic utility of this electrochemical strategy. Scheme 1. Representative significant disulfides. Scheme 2. Three pathwayst osynthesizeunsymmetrical disulfide.

The chemotherapeutic effectiveness of pancreatic ductal adenocarcinoma (PDAC) is severely hampered by insufficient intratumoral delivery of antitumor drugs. Here, we demonstrate that enhanced pancreatic cancer chemotherapy can be achieved by probiotic spore-based oral drug delivery system via gut–pancreas axis translocation. Clostridium butyricum spores resistant to harsh external stress are extracted as drug carriers, which are further covalently conjugated with gemcitabine-loaded mesoporous silicon nanoparticles (MGEM). The spore-based oral drug delivery system (SPORE-MGEM) migrates upstream into pancreatic tumors from the gut, which increases intratumoral drug accumulation by ∼3-fold compared with MGEM. In two orthotopic PDAC mice models, tumor growth is markedly suppressed by SPORE-MGEM without obvious side effects. Leveraging the biological contact of the gut–pancreas axis, this probiotic spore-based oral drug delivery system reveals a new avenue for enhancing PDAC chemotherapy.