手性二茂铁基β-氨基醇的合成及其在催化硼氢化钠/碘对潜手性酮的不对称还原反应中的应用

Synthesis of Chiral Ferrocenyl β-Amino Alcohols and Catalytic Application in Enantioselective Reduction of Prochiral Ketone

从二茂铁和廉价易得的L-缬氨酸、苯丙氨酸出发,合成了4个手性氨基醇衍生的二茂铁基β-氨基醇.研究了它们在催化硼氢化钠/碘对苯乙酮的不对称还原反应的对映选择性.结果表明:二茂铁基氨基醇4、5和6都能诱导得到优势加成产物R-1-苯基-1-乙醇.其中4b以最好89%的产率和65%e.e.值得到产物,而用与4b对应的α-胺基膦氧化物5和6催化时,化学产率和e.e.值分别为81%和38%,82%和32%.

Abstract： Four chiral ferrocenyl β-amino alcohols ligands were synthesized in high yields starting from ferrocene and natural L-amino acids under mild conditions. These chiral ligands were further applied in the asymmetric reduction of acetophenone. The results show that the four chiral ferrocenyl ffamino alcohols iigands can give （R）-1-phenyl 1-ethanol as preponderant product. The best result was given by 4b, and the corresponding （R） 1 phenyl-1 ethanol was isolated in 89% yield with 65% e.e. While the α-ferrocenyl α-aminophosphine oxide 5 and 6 gave （R）-1-phenyl 1-ethanol in 81% yield with 38% e.e and 82% yield with 32% e.e respectively.