Johansen Christian M, Boyd Emily A, Peters Jonas C
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Sci Adv. 2022 Oct 28;8(43):eade3510. doi: 10.1126/sciadv.ade3510. Epub 2022 Oct 26.
Inspired by momentum in applications of reductive photoredox catalysis to organic synthesis, photodriven transfer hydrogenations toward deep (>2 e) reductions of small molecules are attractive compared to using harsh chemical reagents. Noteworthy in this context is the nitrogen reduction reaction (NRR), where a synthetic photocatalyst system had yet to be developed. Noting that a reduced Hantzsch ester (HEH) and related organic structures can behave as 2 e/2 H photoreductants, we show here that, when partnered with a suitable catalyst (Mo) under blue light irradiation, HEH facilitates delivery of successive H equivalents for the 6 e/6 H catalytic reduction of N to NH; this catalysis is enhanced by addition of a photoredox catalyst (Ir). Reductions of additional substrates (nitrate and acetylene) are also described.
受还原性光氧化还原催化在有机合成应用中所展现的发展势头的启发，与使用苛刻的化学试剂相比，光驱动的小分子深度（>2e）还原转移氢化反应颇具吸引力。在此背景下值得注意的是氮还原反应（NRR），目前尚未开发出合成光催化剂体系。鉴于还原型汉斯酯（HEH）及相关有机结构可作为2e/2H光还原剂，我们在此表明，当在蓝光照射下与合适的催化剂（Mo）配合时，HEH有助于为将N催化还原为NH₃的6e/6H反应连续提供H当量；添加光氧化还原催化剂（Ir）可增强这种催化作用。本文还描述了对其他底物（硝酸盐和乙炔）的还原反应。
