Amines alkene epoxidation, iron catalysts

Non-heme iron catalysts containing multidentate nitrogen ligands such as pyri-dines and amines have been studied by various groups [42a, 52-54], Jacobsen and coworkers presented an MMO mimic system for the epoxidation of aliphatic alkenes in which the catalyst self-assembles to form the active species [54] (Scheme 3.5). Interestingly, small amounts of an additive (one equivalent of acetic acid) increased the catalytic performance, presumably due to the intermediate formation of peroxya-cetic acid [55, 56]. The reactions proceeded quickly even with terminal aliphatic alkenes, which are generally considered difficult substrates. Another catalyst system available for the epoxidation of terminal alkenes uses phenanthroline as ligand [57]. 

Mechanistically related to Mn, is the use of Fe as an epoxidation catalyst. Recently, iron complexes with a tetradentate amine core were reported, that were capable of activating H202 without the involvement of hydroxyl radicals [72]. For a variety of substituted as well as terminal alkenes, effective epoxidation... 

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