Question

What products would you expect from the following reactions?

Short answer

In heck reaction,alkyl halide, aryl halide, or pseudo alkyl halide react with electron-deficient species and palladium zero catalysts to give the cross-coupled product.

This reaction is stereoselective, so trans alkene is obtained rather than cis alkene due to steric hindrance during the coupling reaction.

Step-by-step solution

Heck Reaction

In heck reaction,alkyl halide, aryl halide, or pseudo alkyl halide react with electron-deficient species and palladium zero catalysts to give the cross-coupled product.

This reaction is stereoselective, so trans alkene is obtained rather than cis alkene due to steric hindrance during the coupling reaction.

Subpart (a) Excepted product from the given reactant.

Aryl halide 1-(4-bromophenyl)ethanone with an alkene 4-methoxypent-1-ene in the presence of palladium catalyst gives a new C-C bond at the less substituted end of the alkene, usually with trans stereochemistry.

Trans alkene product

Subpart (b) Excepted product from the given reactant.

Alkyl halide (Z)-2-bromopent-2-ene with an alkene 1-methoxy-4vinylbenzene in the presence of palladium catalyst gives a new C-C bond at the less substituted end of the alkene, usually with trans stereochemistry.

Trans alkene product