Electrochemical C−C bond cleavage of cyclopropanes towards the synthesis of 1,3-difunctionalized molecules

Electrochemistry has a lot of inherent advantages in organic synthesis and many redox reactions have been achieved under electrochemical condition. However, the electrochemical C−C bond cleavage and functionalization reactions are less studied. Here we develop electrochemical C−C bond cleavage and 1,3-difuntionalization of arylcyclopropanes under catalyst-free and external-oxidant-free conditions. 1,3-difluorination, 1,3-oxyfluorination and 1,3-dioxygenation of arylcyclopropanes are achieved with a high chemo- and regioselectivity by the strategic choice of nucleophiles. This protocol has good functional groups tolerance and can be scaled up. Mechanistic studies demonstrate that arylcyclopropane radical cation obtained from the anode oxidation and the subsequently generated benzyl carbonium are the key intermediates in this transformation. This development provides a scenario for constructing 1,3-difunctionalized molecules.

Electrochemical C-C Bond Cleavage of Cyclopropanes towards the Synthesis of 1,3-Difunctionalized Molecules

Electrochemistry had a lot of inherent advantages in organic synthesis and many redox reactions have been achieved under electrochemical condition. However, the electrochemical C-C bond cleavage and functionalization reactions are less studied. Here we developed electrochemical C-C bond cleavage and 1,3-difuntionalization of arylcyclopropanes under catalyst-free and external-oxidant-free conditions. 1,3-difluorination, 1,3-oxyfluorination and 1,3-dioxygenation of arylcyclopropanes were achieved with a highly chemo- and regioselectivity by the strategic choice of nucleophiles. This protocol has good functional groups tolerance and can be scaled up. Mechanistic studies demonstrate that arylcyclopropane radical cation yielded from the anode oxidation and the following generated benzyl carbonium are the key intermediates in this transformation. This development provides a new scenario for constructing 1,3-difunctionalized molecules.

Thioester synthesis through geoelectrochemical CO2 fixation on Ni sulfides

Thioester synthesis by CO dehydrogenase/acetyl-CoA synthase is among the most ancient autotrophic metabolisms. Although the preceding prebiotic CO2 fixation routes to thioesters are often suggested, none has any experimentally supported evidence. Here we demonstrate that, under an electrochemical condition realizable in early ocean hydrothermal systems, nickel sulfide (NiS) gradually reduces to Ni0, while accumulating surface-bound CO due to CO2 electroreduction. The resultant partially reduced NiS facilitates thioester (S-methyl thioacetate) formation from CO and methanethiol even at room temperature and neutral pH. This thioester formation can further be enhanced up to a selectivity of 56% by NiS coprecipitating with FeS or CoS. Considering the central role of Ni in the enzymatic process mentioned above, our demonstrated thioester synthesis with the partially reduced NiS could have a direct implication to the autotrophic origin of life.

Thioester Synthesis through Geoelectrochemical CO2 Fixation on Ni Sulfides

Thioester synthesis by CO dehydrogenase/acetyl-CoA synthase is among the most ancient autotrophic metabolisms. Although the preceding prebiotic CO2 fixation routes to thioesters are often suggested, none has any experimentally supported evidence. Here we demonstrate that, under an electrochemical condition realizable in early ocean hydrothermal systems, nickel sulfide (NiS) gradually reduces to Ni0, while accumulating surface-bound CO due to CO2 electroreduction. The resultant partially reduced NiS facilitates thioester (S-methyl thioacetate) formation from CO and methanethiol even at room temperature and neutral pH. This thioester formation can further be enhanced up to a selectivity of 56% by NiS coprecipitating with FeS or CoS. Considering the central role of Ni in the enzymatic process mentioned above, our demonstrated thioester synthesis with the partially reduced NiS could have a direct implication to the autotrophic origin of life.<br>

Thioester Synthesis through Geoelectrochemical CO2 Fixation on Ni Sulfides

Thioester synthesis by CO dehydrogenase/acetyl-CoA synthase is among the most ancient autotrophic metabolisms. Although the preceding prebiotic CO2 fixation routes to thioesters are often suggested, none has any experimentally supported evidence. Here we demonstrate that, under an electrochemical condition realizable in early ocean hydrothermal systems, nickel sulfide (NiS) gradually reduces to Ni0, while accumulating surface-bound CO due to CO2 electroreduction. The resultant partially reduced NiS facilitates thioester (S-methyl thioacetate) formation from CO and methanethiol even at room temperature and neutral pH. This thioester formation can further be enhanced up to a selectivity of 56% by NiS coprecipitating with FeS or CoS. Considering the central role of Ni in the enzymatic process mentioned above, our demonstrated thioester synthesis with the partially reduced NiS could have a direct implication to the autotrophic origin of life.<br>

Thioester Synthesis by Geoelectrochemical CO2 Fixation on Ni Sulfides

<i></i>Thioester synthesis via CO2 fixation by CO dehydrogenase/acetyl-CoA synthase is among the most ancient autotrophic metabolism often suggested to have a prebiotic root. Here we demonstrate that, under an electrochemical condition realizable in early ocean hydrothermal systems, nickel sulfide (NiS) gradually reduces to Ni0, thereby drastically enhancing its capability of driving nonenzymatic CO2 fixation. It catalyzes CO2 electroreduction to CO, concentrates CO on the surface Ni0 sites, and promotes CO condensation to a thioester in the presence of methanethiol. Even greater CO-to-thioester reaction efficiency is realized with NiS coprecipitating with FeS or CoS. Considering the central role of Ni in the enzymatic process mentioned above, our demonstrated thioester synthesis by the partially electroreduced NiS could have a direct implication to the autotrophic origin of life.<br>

Operando X-ray spectroscopic tracking of self-reconstruction for anchored nanoparticles as high-performance electrocatalysts towards oxygen evolution

Operando X-ray absorption spectroscopy (XAS) technique unravels that the CoFe nanoparticles in a new type of lanthana-anchored CoFe catalyst are nearly transformed into unique (Co/Fe)O(OH) under the electrochemical condition, as real active species for oxygen evolution reaction.

Iron-Water Interface under Electrochemical Condition

Spin polarized density functional theory calculations have been performed to characterize the structure of water molecules on iron surface under applied charges. It is found that water molecules of the contact layer take H-down configuration under the negative charge, on the other hand, under the positive charge, they adsorbed on a top site of iron atom, as the applied charge increases, the dissociation of water molecules proceed. In addition, we found that the energy shift of the Fermi level varies linearly in the range from-e to +e, while beyond this range it tends to saturate.