Dihydroxylation reaction Jacobsen epoxidation

While Table 4 describes the situation in 2001 and many additional processes have been reported. The following analysis is still valid. A look at the processes listed in Table 4 shows that hydrogenation of C=C and C=0 is by far the most predominant transformation applied for industrial processes, followed by epoxidation and dihydroxylation reactions. On the one hand, this is due to the broad scope of cataljrtic hydrogenation and on the other hand it could be attributed to the early success of Knowles with the L-dopa process, because for many years, most academic and industrial research was focused on this transformation. The success with epoxidation and dihydroxylation can essentially be attributed to the efforts of Sharpless, Katsuki, and Jacobsen. If one analyzes the structures of the starting materials, it is quite obvious that many of these compounds are often complex and multifunctional, that is, the successful catalytic systems are not only enantioselective but tolerate many functional groups. 

Asymmetric manganese-salen-catalyzed epoxidation of unfunctionalized olefins was reported by Jacobsen et al. [74] in 1990, which allowed the enantioselective epoxidation of unfunctionalized olefins. In particular, the high enantioselectivities obtained for Jacobsen epoxidation on cis-olefins, nicely complement the Sharpless epoxidation and dihydroxylation protocols, which give reduced enantioselectivities for these substrates. The Sharpless and Jacobsen procedures are frequently used asymmetric oxidative reactions in API synthesis. More recently, organocatalytic procedures such as Shi epoxidations [75] were also employed to avoid toxic transition metal catalysts. 

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