2,2′(1-Methylethylidene)bis[4,5-dihydro-5,5-dimethyl-4-phenyl-(4S,4′S)-oxazole

Abstract

For S,S-1, [145439-96-9] C25H30N2O2 (MW 390.23) InChI = 1S/C25H30N2O2/c1-23(2,21-26-19(24(3,4)28-21)17-13-9-7-10-14-17)22-27-20(25(5,6)29-22)18-15-11-8-12-16-18/h7-16,19-20H,1-6H3/t19-,20-/m0/s1 InChIKey = KKVLQJBCBPVJNU-PMACEKPBSA-N For R,R-2, [187106-45-2] C25H30N2O2 (MW 390.23) InChI = 1S/C25H30N2O2/c1-23(2,21-26-19(24(3,4)28-21)17-13-9-7-10-14-17)22-27-20(25(5,6)29-22)18-15-11-8-12-16-18/h7-16,19-20H,1-6H3/t19-,20-/m1/s1 InChIKey = KKVLQJBCBPVJNU-WOJBJXKFSA-N (chiral ligand for enantioselective metal-catalyzed reactions such as the magnesium-catalyzed Diels-Alder reactions of cyclopentadiene and N-crotonyloxazolidinone1, 2 as well as the copper-catalyzed cyclopropenation of olefins with diazomalonates3 and iodonium ylides4, 5 and the aziridination of styrenes6) Physical Data: mp 83–84 °C, S,S-1: −149.5 °(c = 1, CHCl3), Rf 0.20 (tlc, silica gel, 5:2 hexane–EtOAc) Solubility: soluble in common organic solvents. Form Supplied in: prepared as colorless solid. Analysis of Reagent Purity: IR, NMR. Preparative Methods: 1 the pure S,S-enantiomer 1 can be synthesized from (S)-phenylglycine methyl ester in four steps. The amino ester is first converted to the corresponding dimethyl amino alcohol, followed by reaction with 0.5 equiv of dimethylmalonyl chloride, and dehydrative cyclization. Purification: bis(oxazoline) 1 can be purified by silica gel flash column chromatography. Handling, Storage, and Precautions: stored at −20 °C under inert atmosphere to prevent decomposition.