Diastereo-and Enantioselective Propargylation Of 5H-oxazol-4-ones As Enabled By Cu Catalysis

Alkyne containing products are very important in the territory of organic chemistry,medicinal chemistry,and biological chemistry.Terminal alkyne containing products is one of the base component of organic chemistry.Propargyl compounds are very common in natural products,synthetic medicines,elaborate chemicals,and its also important to organic chemistry and medicinal chemistry.Asymmetric propargylic substitution reaction using a Cu\Ti co-catalytic system can been used to synthetic chiral tertiary alcohols compounds with terminal alkyne,can be farther modified and used.In this paper,nine 5H-oxazol-4-ones substrates were synthesized through four steps and twelve propargyl carbonates substr-ates were synthesized through two steps.The condition of the asymmetric propargylic substitution reaction was screened.In this condition:?D,L?-me-Cl pybox?10mol%?as the ligand,Cu?CH₃CN?₄BF₄?5mol%?as the Cu-source,toluene as the solvent,Ti?OⁱPr?₄?10mol%?as the co-catalyst,the reaction offered the87%yield and 88.8%ee as the best result.Substrates with different fun-ctional group were expanded,the yield is 57%-98%and ee is 78%-97%.In this paper,the known compounds were confirmed by?¹HNMR?,the unknown compo-unds were confirmed by?¹HNMR?and(¹³CNMR);the yield in synthesis is the separation yield;the yield in condition screened is the NMR yield determined by?¹HNMR?of the crude reac-tion mixture with 1,3,5-trimethoxybenzene as an internal standard.