Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan).
Angew Chem Int Ed Engl. 2014 May 19;53(21):5356-60. doi: 10.1002/anie.201403215. Epub 2014 Apr 16.
The development of visible-light-induced photocatalysts for chemoselective functional group transformations has received considerable attention. Polyoxometalates (POMs) are potential materials for efficient photocatalysts because their properties can be precisely tuned by changing their constituent elements and structures and by the introduction of additional metal cations. Furthermore, they are thermally and oxidatively more stable than the frequently utilized organometallic complexes. The visible-light-responsive tetranuclear cerium(III)-containing silicotungstate TBA6[{Ce(H2O)}2{Ce(CH3CN)}2(μ4-O)(γ-SiW10O36)2] (CePOM; TBA=tetra-n-butylammonium) has now been synthesized; when CePOM was irradiated with visible light (λ>400 nm), a unique intramolecular Ce(III)-to-POM(W(VI)) charge transfer was observed. With CePOM, the photocatalytic oxidative dehydrogenation of primary and secondary amines as well as the α-cyanation of tertiary amines smoothly proceeded in the presence of O2 (1 atm) as the sole oxidant.
可见光诱导光催化剂用于选择性官能团转化的发展受到了广泛关注。多金属氧酸盐（POMs）是高效光催化剂的潜在材料，因为通过改变其组成元素和结构以及引入额外的金属阳离子，可以精确调整它们的性质。此外，与经常使用的有机金属配合物相比，它们在热和氧化方面更稳定。现在已经合成了具有可见光响应的四核铈(III)含硅钨酸盐 TBA6[{Ce(H2O)}2{Ce(CH3CN)}2(μ4-O)(γ-SiW10O36)2]（CePOM；TBA=四正丁基铵）；当 CePOM 受到可见光（λ>400nm）照射时，观察到独特的分子内铈(III)到 POM(W(VI))电荷转移。使用 CePOM，在氧气（1atm）作为唯一氧化剂的存在下，伯胺和仲胺的光催化氧化脱氢以及叔胺的α-氰化反应顺利进行。
