Comparison of Phosphonium and Sulfoxonium Ylides in Ru(II)-Catalyzed Dehydrogenative Annulations: A Density Functional Theory Study

Molecules, Journal Year: 2025, Volume and Issue: 30(9), P. 1883 - 1883

Published: April 23, 2025

Density functional theory calculations have been performed to explore the detailed mechanism of a ruthenium-catalyzed dehydrogenative annulation between α-carbonyl phosphonium ylide (A) and sulfoxonium (B). The proposed catalytic cycles consist several elementary steps in succession, namely C–H activation A, insertion B, reductive elimination, protodemetallation, an intramolecular Wittig reaction, which is rate-limiting, with free energy barrier 31.7 kcal/mol. As A B are both capable being substrate carbene precursor, there potentially four competing pathways including homo-coupling reactions. Further demonstrate that more reactive step than while opposite conclusion true for step, can successfully explain fact solely observed product originated from use as precursor. Molecular electrostatic potential, charge decomposition, electron density difference analyses were understand distinct behaviors two ylides nature key ruthenium–carbene intermediate.

Language: Английский

Iridium(III)-Catalyzed Cyclization of Oximes with Iodonium Ylides: Synthesis of Multisubstituted Heterocyclic N-Oxides

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: May 29, 2025

Iridium(III)-catalyzed regioselective cyclization of substituted oximes with iodonium ylides has been described. This methodology offered multisubstituted heterocyclic N-oxides under mild reaction conditions in a redox-neutral manner. The was also compatible vinyl oximes. Additionally, substrate diversification carried out to illustrate the synthetic application protocol. A possible mechanism involving C-H bond activation proposed as well supported by isolation key five-membered iridacycle intermediate.

Language: Английский