Quiz - Carbon-Carbon Bond Formation - 3 | Carbon-Carbon Bond Formation
Organic Chemistry 3 - Quiz - Carbon-Carbon Bond Formation - 3
Which reaction would you typically use to couple aryl halides with alkenylboronic acids in the presence of a palladium catalyst under mild conditions?
The Suzuki Reaction is the correct choice because it specifically involves the coupling of aryl halides with organoboron compounds, such as alkenylboronic acids, using a palladium catalyst. This method is known for its mild conditions and tolerance of a wide range of functional groups.
In a Heck reaction, which type of palladium species is responsible for the oxidative addition step with an aryl halide?
Pd(0) is the correct answer because in the Heck reaction, the catalytic cycle begins with a Pd(0) species undergoing oxidative addition to an aryl halide to form a Pd(II) complex, which is a crucial step in the mechanism.
What is a key benefit of using organocuprate reagents (Gilman reagents) for carbon-carbon bond formation?
The selective 1,4-addition to enones is a hallmark of organocuprate reagents (Gilman reagents), distinguishing them from other metal organometallics in their ability to add to the carbon 4 of α,β-unsaturated systems.
Which reagent is specifically employed in the Simmons-Smith reaction for the cyclopropanation of alkenes?
The combination of zinc-copper and iodomethane is used in the Simmons-Smith reaction to generate an active carbenoid species that performs the cyclopropanation of alkenes.
What role does the stereochemistry of the starting materials play in the outcome of the Heck reaction?
The stereochemistry of the starting materials in the Heck reaction influences the stereochemistry of the product, with retention of stereochemistry observed at the carbon-carbon bond forming site.
Which of the following reactions relies on the metallocarbene mechanism for carbon-carbon bond formation?
The Simmons-Smith Reaction utilizes a metallocarbene species, typically generated from zinc-copper and iodomethane, which then adds to an alkene to form a cyclopropane.
What is a key property that enhances the stability and reactivity of carbenes in metathesis reactions?
In metathesis reactions, the coordination of carbenes to a transition metal greatly enhances their stability and reactivity. This allows them to participate effectively in the metathesis process.
What distinguishes terminal alkenes as excellent substrates for metathesis reactions?
Terminal alkenes produce ethylene gas as a byproduct in metathesis reactions, which drives the reaction towards completion by escaping from the reaction mixture.
During which reaction would you expect a migratory insertion of an alkene into a palladium hydride species to occur?
The migratory insertion of an alkene into a palladium hydride is a step in the Heck reaction, where after oxidative addition of an aryl halide to Pd(0), the resulting Pd(II) species undergoes alkene insertion before reductive elimination to form the new carbon-carbon bond.
What function does copper serve in a typical Sonogashira cross-coupling reaction?
In the Sonogashira reaction, copper typically serves as a co-catalyst, aiding the palladium-catalyzed cross-coupling of aryl halides with terminal alkynes to form alkynylated products.