美国加州大学伯克利分校John F. Hartwig团队报道了通过碳酸酐酶催化氢化锌非生物还原硅烷类酮。相关研究成果发表在2021年2月18日出版的《自然—化学》。

尽管在合成的过渡金属催化剂的反应中存在这样的中间产物，但是通过单核金属氢化物进行的酶促反应在自然界中是未知的。如果金属酶可以通过这些非生物的中间产物进行反应，那么酶催化反应的范围就会扩大。

研究表明含锌碳酸酐酶催化氢化物转移从硅烷到酮具有很高的对映选择性。研究报告的力学数据提供了强有力的证据，证明该过程涉及一个单核氢化锌。研究工作表明，非生物硅烷可以作为酶催化过程中的还原当量物，而电正金属单体氢化物在质子环境中通常是不稳定的，可以作为酶催化过程中的催化中间体。

总的来说，该研究工作填补了分子催化和生物催化转化类型之间的空白。

附：英文原文

Title: Abiotic reduction of ketones with silanes catalysed by carbonic anhydrase through an enzymatic zinc hydride

Author: Pengfei Ji, Jeeyoung Park, Yang Gu, Douglas S. Clark, John F. Hartwig

Issue&Volume: 2021-02-18

Abstract: Enzymatic reactions through mononuclear metal hydrides are unknown in nature, despite the prevalence of such intermediates in the reactions of synthetic transition-metal catalysts. If metalloenzymes could react through abiotic intermediates like these, then the scope of enzyme-catalysed reactions would expand. Here we show that zinc-containing carbonic anhydrase enzymes catalyse hydride transfers from silanes to ketones with high enantioselectivity. We report mechanistic data providing strong evidence that the process involves a mononuclear zinc hydride. This work shows that abiotic silanes can act as reducing equivalents in an enzyme-catalysed process and that monomeric hydrides of electropositive metals, which are typically unstable in protic environments, can be catalytic intermediates in enzymatic processes. Overall, this work bridges a gap between the types of transformation in molecular catalysis and biocatalysis.

DOI: 10.1038/s41557-020-00633-7

Source: https://www.nature.com/articles/s41557-020-00633-7