Mizoroki-Heck Reaction Using Immobilized Aryl Halides

1 Mizoroki-Heck Reaction Using Immobilized Aryl Halides 

Other examples involve Mizoroki-Heck couplings of aryl bromides using a sulfur linker cleaved nnder very mild conditions in the presence of samarium iodide [17, 18], the solid-supported hyperbranched polymerization of phenylacetylene derivatives [19] or a 

In general, intermolecular Mizoroki-Heck reactions using immobilized alkenes are not as common as the variant that deals with solid-supported aryl halides, but we will come across another example in Section 14.2,3 on multicomponent Mizoroki-Heck reactions. 

Among the previously mentioned advantages of sohd-phase synthesis, the pseudodilution effect particularly affects the intramolecular variant of the Mizoroki-Heck reaction, commonly resulting in increased yields and leading to the most complex stractures obtained by Mizoroki-Heck reactions on solid phase. 

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The Mizoroki-Heck reaction can either be performed on immobilized aryl halides with soluble alkenes [13] or alkynes or with the latter being attached to solid phase and free aryl halides. When performed on the same type of resin and using identical catalyst cocktails, however, it generally seems preferable to use immobilized aryl halides with soluble alkenes rather than doing it the other way around [14]. Both possibilities have been reported and will be discussed below [11]. 

A non-covalent immobilization of Heck catalyst on silica (SILP concept) has been realized by Hagiwara et al. [217]. They used a silica surface, supported with Pd(OAc)2 dissolved in [BMIM][PFe]. This catalyst was appUed to the Mizoroki-Heck reaction of aryl halides with acrylate without a ligand in n-dodecane as solvent. It was six times reused and the overall TON reached 68 400 (for more details see Section 5.6). 

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