Applied Organometallic Chemistry. Schwartz'S Reagent

In 1974, Jeffrey Schwartz published the results of his researches on an organometallic compound of the zirconocene family, bis(eta(5)-cyclopentadienyl)chlorohydrurozirconium(IV), [(eta(5)-C5H5)(2)Zr(H)Cl]. This Zr(IV) complex had the property of adding the Zr-H group to unsaturated substrates, especially olefins and acetylenes, a reaction known as hydrozirconation. The alkenylzirconocenes thus obtained showed activity in reactions on the unsaturated group, which could be transformed into alcohols, aldehydes, esters and carboxylic acids, nitriles or alkyl halides. This research was broadly accepted by the scientific community and began the development of a wide line of research related to the hydrozirconation reaction, and [(eta(C5H5)-C-5)(2)Zr(H)Cl] was called "Schwartz's reagent". A review of the original literature in the applied organometallic chemistry area, allows corroborating the importance of Schwartz's reagent and the hydrozirconation reaction that, connected with the transmetalation and Negishi coupling reactions, constitute a powerful tool for the total synthesis of organic compounds of interest for fine chemistry. This article presents a review of the most relevant aspects related to Schwartz's reagent in the period 1974-2020, and discusses some aspects involved with the applications of the hydrozirconation reaction, a reaction on which expectations remain high, consider the possibility of obtaining analogous organozirconium compounds that, independently or in combination with Schwartz's reagent, can act as determining steps in the total synthesis of chemical compounds relevant for the pharmaceutical area.