|
چکیده
|
C2-symmetric chiral bisoxazoline ligands have emerged as an efficient class of ligands in an increasing number of asymmetric transformations. [1,2]. Here in two chiral (S,S,S)-2,2′-bitolyl bisoxazoline and (S,R,S)-2,2′-bitolyl bisoxazoline ligands were synthesised in high yield and enantiomeric excess using inexpensive and available starting material 3-methyl benzoic acid. Chiral (S,S,S)-2,2′-bitolyl bisoxazoline ligand along with copper (I) hexaflurophosphate as counter ion was used as a catalyst in asymmetric allylic oxidation of cyclohexene with t-butylperbenzoate(Scheme1) [3,4]. The highest yield and optical rotation for the chiral allyl ester product was obtained in the presence of phenyhydrazine as an electron donor and molecular sieves in acetone (Scheme1) [3,4].
|