An alternative approach to chiral 2-[1 '-(diphenylphosphanyl)ferrocenyl]-4,5-dihydrooxazoles

The reaction of 1'-(diphenylphosphanoyl) ferrocenecarbonyl chloride, genera ted in situ by the reaction of 1'-(diphenylphosphanoyl)ferrocenecarboxylic acid and oxalyl chloride, with chiral aminoalcohols gave amidoalcohols [Fe( eta (5)-C5H4P(O)Ph-2)(eta (5)-C5H4C(O)NHCH 13, (R = i-Pr, (S); R = i-Pr, (R ); R = t-Bu, (S) and R = Ph, iR). The amidoalcohols 13 were converted to 2- [1'-(diphenylphosphanoyl)ferrocen-1-yl]-4,5-dihydrooxazolcs 14 by ring-clos ing reaction with a tosyl chloride-triethylamine mixture. Subsequent reduct ion of 14 with trichlorosilane in the presence of triethylamine afforded th e corresponding 2-[1'-(diphenylphosphanyl)ferrocenyl]-4,5-dihydrooxazol 10. Compounds 13d, 14d and 10d were subjected to a detailed H-1,C-13 and P-31 NMR analyses. CD spectra of all 10 were measured. trans-Dichlorobis{(S)-2-[ 1'-(diphenylphosphanyl)ferrocenyl]-4-isopropyl-4-5-dihydrooxazole-kappaP)pa lladium(II) (15) was synthesised and its solid-state structure was determin ed by single-crystal X-ray diffraction.