Hartwig-Fu protocol

NaaCOs, affords high yields in the reaction of 4-chloroanisole (71) with -butyl acrylate (38) in DMA at 140 °C. This is likely to be the highest temperature that has appeared in literature for hgand-accelerated Mizoroki-Heck reactions of unreactive aryl chlorides. In the same protocol, several bulky secondary phosphines, namely bis(adamantyl)phosphine, bis(norbomyl)phosphine and f-BuaPH, were also operative yet inferior to f-BusP [133]. Unlike the Hartwig-Fu protocol, this method has found no application so far, which is why its scope cannot be reliably assessed. 

Figure 2.9 Compounds made using the Hartwig-Fu protocol.

Despite electron-rich bulky side-arms as in phosphine pincers 190,191 [245] or 192 [246] (Figure 2.24), these complexes behave strikingly different from their respective dialkyl or trialkylphosphine palladium complexes the latter complexes show t)q)e3 activtity (cf. Hartwig-Fu protocol see above). PCP-pincer complexes 190-192, however, are typical SRPCs exclusively suitable for type 1 reactions of aryl iodides and activated aryl bromides (Table 2.9, entries 1-6). Ligand-acceleration effects are not observed, which unequivocally underlines that the cleavage of these pincer complexes under the reacation conditions occurs to release nonphosphine palladium complexes with indeterminate coordination shell. 

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