A Single Terminal NiII-OH Catalyst for Direct Julia-Type Olefination and α-Alkylation Involving Sulfones and Alcohols

• Published in: Chemistry : a European journal 2024-06, Vol.30 (35), p.e202400337
• Main Authors: Pandey, Prabhakar K, Patra, Moumita, Ranjan, Prabodh, Kumar Pal, Nilay, Choudhary, Sanjay, Bera, Jitendra K
• Format: Article
• Language: English
• ISSN: 1521-3765; 1521-3765
• DOI: 10.1002/chem.202400337

A terminal [NiII-OH] complex 1, supported by triflamide-functionalized NHC ligands, showed divergent reactivity for the reaction of sulfone with alcohol, contingent on base concentration, temperature, and time. Julia-type olefination of alcohols with sulfones was achieved using one equiv. of base, whereas lowering base loading to 0.5 equiv. afforded α-alkylated sulfones. Besides excellent substrate scope and selectivity, biologically active stilbene derivatives DMU-212, pinosylvin, resveratrol, and piceatannol were synthesized in high yield under Julia-type olefination conditions. An extensive array of controlled experiments and DFT calculations provide valuable insight on the reaction pathway.A terminal [NiII-OH] complex 1, supported by triflamide-functionalized NHC ligands, showed divergent reactivity for the reaction of sulfone with alcohol, contingent on base concentration, temperature, and time. Julia-type olefination of alcohols with sulfones was achieved using one equiv. of base, whereas lowering base loading to 0.5 equiv. afforded α-alkylated sulfones. Besides excellent substrate scope and selectivity, biologically active stilbene derivatives DMU-212, pinosylvin, resveratrol, and piceatannol were synthesized in high yield under Julia-type olefination conditions. An extensive array of controlled experiments and DFT calculations provide valuable insight on the reaction pathway.