山东大学王瑶团队报道了六价碲基硫键合催化平台——高催化活性和选择性控制。相关研究成果发表在2025年1月13日出版的《美国化学会杂志》。

该文中，研究人员开发了一种能够解决反应性和选择性问题的六价碲基硫族键合催化平台。该研究首次证明，六价碲盐可以作为一类高活性的硫族键合催化剂。这些六价催化剂中的碲中心只有一个暴露的相互作用位点，从而为控制反应选择性提供了有利条件。这些六价碲催化剂的优点，通过它们在C-F键活化氰化二氟环丙烯中的显著催化活性得到了证明，否则在强路易斯酸的催化下反应性低，或者代表性的二价/四价碲基供体无法获得。

六价碲催化剂的催化活性进一步突出，因为它能够解决与强路易斯酸方法相关的先前未解决的反应性问题，即在二氟环丙烯的官能化中，使用一些反应性较低的甲硅烯醇醚作为亲核试剂。该催化平台在不同反应体系中的广泛应用证明了其通用性。

六价碲催化剂可以区分糖基受体中的两个相似的游离OH基团，在二糖的合成中实现优异的区域和立体选择性，其中四价碲催化剂的反应性和选择性较低。机理研究表明，催化剂糖基供体-受体三元超分子复合物是有效的。

附：英文原文

Title: A Hexavalent Tellurium-Based Chalcogen Bonding Catalysis Platform: High Catalytic Activity and Controlling of Selectivity

Author: Xinxin Li, Yi Liu, Wei Wang, Yao Wang

Issue&Volume: January 13, 2025

Abstract: Herein, we describe a hexavalent tellurium-based chalcogen bonding catalysis platform capable of addressing reactivity and selectivity issues. This research demonstrates that hexavalent tellurium salts can serve as a class of highly active chalcogen bonding catalysts for the first time. The tellurium centers in these hexavalent catalysts have only one exposed interaction site, thus providing a favorable condition for the controlling of reaction selectivity. The advantages of these hexavalent tellurium catalysts were demonstrated by their remarkable catalytic activity in the cyanidation of difluorocyclopropenes through C–F bond activation, which otherwise were low reactive under the catalysis of strong Lewis acids or inaccessible by representative divalent/tetravalent tellurium-based donors. The catalytic activity of the hexavalent tellurium catalyst was further highlighted by its capability to address a previously unresolved reactivity problem associated with the strong Lewis acid approach, upon using some less reactive silyl enol ethers as nucleophiles in the functionalization of difluorocyclopropenes. The generality of this catalysis platform was demonstrated by its versatile application in different reaction systems. The hexavalent tellurium catalyst can differentiate two similar free OH groups in glycosyl acceptors to achieve excellent regio- and stereoselectivity in the synthesis of disaccharides, in which the tetravalent tellurium catalyst gave low reactivity and selectivity. Mechanistic investigation suggests that a catalyst-glycosyl donor–acceptor ternary supramolecular complex is operative.

DOI: 10.1021/jacs.4c13004

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c13004