What is a sigmatropic reaction in organic chemistry?
Q: What is a sigmatropic reaction in organic chemistry?
A: A sigmatropic reaction is a pericyclic reaction that involves an uncatalyzed intramolecular process, and changes one σ-bond into a different σ-bond.
Q: Does a sigmatropic reaction involve a catalyst?
A: An actual sigmatropic reaction does not usually involve a catalyst, although some sigmatropic reactions can be catalysed by a Lewis acid.
Q: What does the term "sigmatropic" mean?
A: The term "sigmatropic" is a compound word composed of "sigma," which refers to single carbon-carbon bonds, and the Greek word "tropos," meaning turn.
Q: What kind of reaction is a sigmatropic reaction?
A: A sigmatropic reaction is a rearrangement reaction, meaning that the bonds in a molecule shift between atoms without any atoms leaving or new atoms added to the molecule.
Q: What happens in an intramolecular sigmatropic reaction?
A: In an intramolecular sigmatropic reaction, a substituent moves from one part of a π-bonded system to another part with simultaneous rearrangement of the π system.
Q: Are there any well-known sigmatropic rearrangements?
A: Some of the most well-known sigmatropic rearrangements are the [3,3] Cope rearrangement, Claisen rearrangement, Carroll rearrangement, and Fischer indole synthesis.
Q: Do sigmatropic reactions often involve transition-metal catalysts?
A: Yes, sigmatropic reactions often have transition-metal catalysts that form intermediates in analogous reactions.
