ABSTRACT

Symmetric and asymmetric dihydroxylation reactions catalyzed by osmium have emerged as the most efficient route in the one-step synthesis of diols. This is because on an industrial scale 1,2-diols are prepared via a two-step procedure. Still, it is a challenge to prepare and apply osmium catalysts in dihydroxylation catalysis because of their safety and environmental implications; e.g., volatile, highly toxic, product contamination, etc. To date, few efforts were reported to comprehensively overcome these drawbacks with great success by heterogenizing to an insoluble matrix, including diminishment in catalytic performance. Hence, the need for efficacious solid-supported osmium catalysts to subdue these difficulties is a topic of great importance. This mini review provides a concise overview of some of the most encouraging solid-supported osmium catalysts reported over the last few years, which proved to be more efficient under mild conditions as opposed to other immobilized osmium catalytic systems. The summary discusses the latest developments in the synthetic heterogenizing and homogenization strategies, structure analysis and investigation toward symmetric and asymmetric dihydroxylation for diol production. Specific emphasis is focused on their mechanistic considerations, their reusability and improvement in their safety, and environmental implications.

摘要

由锇催化的对称和不对称二羟基化反应已成为一步合成二醇的最有效途径。这是因为在工业规模上，1,2-二醇是通过两步程序制备的。尽管如此，由于锇催化剂的安全性和环境影响，在二羟基化催化中制备和应用锇催化剂仍然是一个挑战。例如，挥发性、剧毒、产品污染等。迄今为止，很少有报道称通过异质化到不溶性基质来全面克服这些缺点并取得巨大成功，包括催化性能降低。因此，需要有效的固体负载锇催化剂来克服这些困难是一个非常重要的话题。这篇简短的综述简要概述了过去几年报道的一些最令人鼓舞的固体负载锇催化剂，与其他固定锇催化系统相比，这些催化剂在温和条件下更有效。该摘要讨论了合成异质化和均质化策略、结构分析和研究用于二醇生产的对称和不对称二羟基化的最新进展。特别强调它们的机械考虑、它们的可重用性和安全性的改进以及环境影响。该摘要讨论了合成异质化和均质化策略、结构分析和研究用于二醇生产的对称和不对称二羟基化的最新进展。特别强调它们的机械考虑、它们的可重用性和安全性的改进以及环境影响。该摘要讨论了合成异质化和均质化策略、结构分析和研究用于二醇生产的对称和不对称二羟基化的最新进展。特别强调它们的机械考虑、它们的可重用性和安全性的改进以及环境影响。