In conventional homogeneous catalysis, supporting ligands act as spectators that do not interact directly with substrates. However, in metal–ligand cooperative catalysis, ligands are involved in facilitating reaction pathways that would be less favourable were they to occur solely at the metal centre. This catalysis paradigm has been known for some time, in part because it is at play in enzyme catalysis. For example, studies of hydrogenative and dehydrogenative enzymes have revealed striking details of metal–ligand cooperative catalysis that involve functional groups proximal to metal active sites. In addition to the more well-known [FeFe]-hydrogenase and [NiFe]-hydrogenase enzymes, [Fe]-hydrogenase, lactate racemase and alcohol dehydrogenase each makes use of cooperative catalysis. This Perspective highlights these enzymatic examples of metal–ligand cooperative catalysis and describes functional bioinspired molecular catalysts that also make use of these motifs. Although progress has been made in developing molecular catalysts, considerable challenges will need to be addressed before we have synthetic catalysts of practical value.

在常规的均相催化中，支撑配体充当不与底物直接相互作用的旁观者。但是，在金属-配体协同催化中，配体参与促进反应途径，如果它们仅在金属中心发生，则反应路径将是不利的。这种催化范例已经知道了一段时间，部分是因为它在酶催化中起作用。例如，对氢化酶和脱氢酶的研究揭示了金属-配体协同催化的惊人细节，涉及金属活性位点附近的官能团。除了更著名的[FeFe]-加氢酶和[NiFe]-加氢酶外，[Fe]-加氢酶，乳酸消旋酶和醇脱氢酶均利用协同催化作用。本《观点》重点介绍了金属-配体协同催化的这些酶促实例，并描述了也利用这些基序的功能性生物启发分子催化剂。尽管在开发分子催化剂方面已取得进展，但在我们获得具有实用价值的合成催化剂之前，仍需要解决相当大的挑战。