Synthesis of α-chiral phosphine sulfides via non-covalent organocatalysis

Abstract

Despite rapid advances in phosphine-containing compound as a privileged ligand for transition metal catalysis, synthesis and coordination chemistry are underexplored for the phosphine sulfide analogs. In this article, we report the enantioselective phospha-Michael addition reaction that leads to α-chiral phosphine sulfide. An independent hydrogen-bonding co-catalyst is found essential to high enantioselectivity (up to 98% yield and 95% enantiomeric excess [ee]). Divergent derivatizations under mild conditions are also attempted for the generic phosphine and phosphine oxide compounds, further emphasizing the bridge role of phosphine sulfide. An X-ray diffraction structure of κ 3 -NNS palladium complex also authenticates the coordination ability of p = S moiety. Combination of NHC and hydrogen bonding donor catalysis α-Chiral phosphine sulfides Downstream derivatizations κ 3 -NNS palladium complex In an effort to diversify the family of phosphine ligands, Li et al. report the orchestration of NHC catalysis and an H-bond donor as a straightforward synthetic strategy to yield α-chiral phosphine sulfides. Preliminary results for downstream derivatization and metal chelation further demonstrate the applications for p = S ligands.