MacDiarmid Institute for Advanced Materials and Nanotechnology, Institute of Fundamental Sciences , Massey University , Palmerston North , 4442 New Zealand.
J Am Chem Soc. 2019 Jan 30;141(4):1577-1582. doi: 10.1021/jacs.8b11221. Epub 2019 Jan 15.
Controlling chemical reactions in porous heterogeneous catalysts is a tremendous challenge because of the difficulty in producing uniform active sites that can be tuned with precision. However, analogous to enzymes, when a catalytic pocket provides complementary close contacts and favorable intermolecular interactions with the reaction participants, the reaction efficiency and selectivity may be tuned. Here, we report an isoreticular family of catalysts based on the multicomponent metal-organic framework MUF-77. The microenvironment around the site of catalysis was successfully programmed by introducing functional groups (modulators) to the organic linkers at sites remote from the catalytic unit. The framework catalysts produced in this way exhibit several unique features, including the simultaneous enhancement of both reactivity and stereochemical selectivity in aldol reactions, the ability to catalyze Henry reactions that cannot be accomplished by homogeneous analogs, and discrimination between different reaction pathways (Henry versus aldol) that compete for a common substrate.
在多孔异相催化剂中控制化学反应是一项巨大的挑战，因为很难产生可以精确调节的均匀活性位。然而，类似于酶，当催化口袋与反应参与者提供互补的紧密接触和有利的分子间相互作用时，反应效率和选择性可以被调节。在这里，我们报道了一类基于多组分金属有机骨架 MUF-77 的同构系列催化剂。通过在远离催化单元的位置的有机连接体上引入官能团（调节剂），成功地对催化位点周围的微环境进行了编程。以这种方式制备的骨架催化剂具有几个独特的特征，包括同时提高了羟醛反应的反应性和立体化学选择性，能够催化均相类似物无法完成的 Henry 反应，以及区分竞争同一底物的不同反应途径（Henry 与羟醛）。
