Reactions with Alkenes Mizoroki-Heck Reaction

2 Reactions with Alkenes (Mizoroki-Heck Reaction) [Pg.109]

Direct alkenylation of benzene derivatives with alkenes was reported by Fujiwara in 1967 and via mercuration by Heck in 1968 using a stoichiometric amount of Pd(II) salts [2], Then, inspired by the discovery of oxidative addition of iodoben-zene to Pd(PPh3)4 to generate Ph-Pd-I by Fitton in 1968 [3], Mizoroki and Heck independently reported the alkenylation of benzene derivatives by the reaction of [Pg.109]

HR consists of three elemental reactions (1) oxidative addition of an organic halide to form arylpalladium halides (2) insertion of an alkene to form the alkyl-palladium 17 (or carbopalladation of alkene) and (3) dehydropalladation (jS-H elimination) to give the arylalkenes 18 or conjugated dienes. [Pg.111]

The stereochemistry of the insertion (carbopalladation) is syn addition. The syn addition of Ar-PdX to an alkene generates ff-(j6-aryl)alkylpalladiums 17. Then internal rotation around the former double bond occurs, making the syn j6-H elimination possible to give the /ram -alkenes 18. [Pg.111]

As supporting evidence of the syn addition, the syn elimination mechanism, Fu obtained only the E-isomer 19 as a kinetic product of the reaction of methyl trans-ciimamate with deuterated bromobenzene at room temperature using Pd2(dba)3 and P(r-Bu)3. Under thermodynamic control at 120 °C, an E, Z-mixture (1 1) was formed [7]. [Pg.111]

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