Department of Organic Chemistry, The Hebrew Unviersity of Jerusalem, Jerusalem, 91904, Israel.
Algemene Chemie, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
Angew Chem Int Ed Engl. 2020 May 11;59(20):7915-7920. doi: 10.1002/anie.201916592. Epub 2020 Mar 13.
This contribution follows the recent remarkable catalysis observed by Groves et al. in hydrogen-abstraction reactions by a) an oxoferryl porphyrin radical-cation complex [Por Fe (O)L ] and b) a hydroxoiron porphyrazine ferric complex [PyPzFe (OH)L ], both of which involve positively charged substituents on the outer circumference of the respective macrocyclic ligands. These charge-coronated complexes are analogues of the biologically important Compound I (Cpd I) and synthetic hydroxoferric species, respectively. We demonstrate that the observed enhancement of the H-abstraction catalysis for these systems is a purely electrostatic effect, elicited by the local charges embedded on the peripheries of the respective macrocyclic ligands. Our findings provide new insights into how electrostatics can be employed to tune the catalytic activity of metalloenzymes and can thus contribute to the future design of new and highly efficient hydrogen-abstraction catalysts.
这一贡献是继 Groves 等人最近在氢提取反应中观察到的显著催化作用之后的进一步研究：a）氧代铁卟啉自由基阳离子配合物[PorFe(O)L]和 b）羟基金属卟啉嗪铁配合物[PyPzFe(OH)L]，这两种配合物都涉及到各自大环配体外围的正电荷取代基。这些带正电荷的配合物分别是生物重要的化合物 I (Cpd I)和合成羟基金属物种的类似物。我们证明，这些体系中观察到的氢提取催化增强是纯粹的静电效应，是由各自大环配体外围嵌入的局部电荷引起的。我们的发现为静电如何被用来调节金属酶的催化活性提供了新的见解，从而为未来设计新型高效的氢提取催化剂做出贡献。
