Catalytic Olefin Transpositions Facilitated by Ruthenium N,N,N-Pincer Complexes

Area of Science:

• Organometallic Chemistry
• Catalysis
• Organic Synthesis

Background:

• Olefin isomerization and transposition are fundamental transformations in organic synthesis.
• Development of efficient and selective catalysts for these reactions remains an active area of research.
• Ruthenium complexes with pincer ligands have shown promise in various catalytic applications.

Purpose of the Study:

• To develop novel N,N,N-pincer ruthenium hydride complexes for olefin transposition/isomerization.
• To investigate the catalytic activity, selectivity, and scope of these complexes.
• To explore the potential for cascade reactions using the transposition products.

Main Methods:

• Synthesis and characterization of a series of N,N,N-pincer (1,3-bis(2-pyridylimino)isoindoline) Ru-hydride complexes.
• Evaluation of catalytic performance in olefin transposition/isomerization reactions under mild conditions.
• Assessment of regioselectivity and diastereoselectivity.
• Investigation of air-stable Ru-chloride derivatives for benchtop applications.
• Demonstration of one-pot cascade sequences.

Main Results:

• The Ru-hydride complexes effectively catalyzed olefin transposition/isomerization with excellent yields, regioselectivity, and diastereoselectivity.
• Reactions proceeded efficiently at room temperature for most substrates in short reaction times.
• Air-stable Ru-chloride derivatives showed comparable reactivity, enhancing synthetic versatility and enabling benchtop setup.
• The products of the transposition reactions were successfully utilized in one-pot cascade sequences.

Conclusions:

• N,N,N-pincer Ru-hydride complexes are highly effective catalysts for olefin transposition/isomerization.
• The developed protocol offers mild reaction conditions, high efficiency, and excellent selectivity.
• The air-stable nature and versatility of these catalysts open new avenues for synthetic applications, including cascade reactions.