Chelate-controlled oxidative Heck

Besides the one-pot process described above, the White Reagent catalyzes a chelate-controlled oxidative Heck arylation between a wide range of a-olefins and organoborane compounds in good yields and with excellent regio-and stereoselectivities (Figure 6). Unlike other Heck arylation methods, no Pd-H isomerization is observed under the mild reaction conditions. Aryl boronic acids, styrenylpinacol boronic esters, and aryl potassium trifluoroborates (activated with boric acid) are all compatible with the general reaction conditions. 

Recently, Yahiaoui et al. developed a chelation-controlled palladium-catalyzed Heck-Mizoroki/Suzuki-Miyaura domino reaction involving metal-coordinating dimethylaminoethyl vinyl ethers and various electron-deficient and electron-rich arylboronic acids by the use of p-Bq as the oxidant [22] (Scheme 6.13). The two-carbon tethered dimethylamino moiety, which could combine with p-Bq for the stabilization of the o-alkylpalladium(II) intermediate 56 and formation of the dia-rylated products 57, is assumed to be crucial for avoiding the formation of Heck products 58. 

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