Sulfur Vacancy-Promoted Highly Selective Electrosynthesis of Functionalized Aminoarenes via Transfer Hydrogenation of Nitroarenes with H2O over a Co3S4- x Nanosheet Cathode

Developing a selective hydrogenation strategy over a low-cost electrocatalyst, especially with an inexpensive and safe hydrogen source for efficient synthesis of aminoareneswith fragile functional groups, is extremely desirable. Herein, using H2O as the hydrogen source, Ti mesh-supported Co3S4 ultrathin nanosheets with sulfur vacancies (denoted as Co3S4-x NS) have been demonstrated to be a highly efficient cathode for selective transfer hydrogenation of nitroarenes to corresponding aminoarenes at low potential. D2O-labeling experiments confirmed the hydrogen origin. Without sulfur vacancies, the products were a mixture of aminoarenes and azoxyareneswith lowselectivity. This method can deliver a variety of aminoarenes with outstanding selectivity and excellent functional group compatibility with highly reducible groups (e.g., C-I, C- Br, C=O, C=C, C= N, C=N, and C=C). The experimental and theoretical results have revealed that sulfur vacancies can enhance the selective specific adsorption of the nitro group and promote intrinsic activity to form active hydrogen from water electrolysis, thus resulting in high selectivity and outstanding fragile functional groups tolerance.

Automated summary

A selective hydrogenation strategy utilizing H2O as the hydrogen source, combined with the design of sulfur vacancies, has been demonstrated to be highly efficient in converting nitroarenes to aminoarenes at low potential using Ti mesh-supported Co3S4 ultrathin nanosheets. This method shows outstanding selectivity and compatibility with highly reducible functional groups.