D - 甘露醇衍生的新型手性配体的合成及其在不对称催化环氧化反应中的应用

合成了手性配体1,2,5,6-O-二异丙基-D-甘露醇(III)以及1,3,4,6-O-二亚苄基-D-甘露醇(IV)及其衍生物并对起结构进行了表征,其中1,3,4,6-O-对氯二亚苄基-D-甘露醇(V),1,3,4,6-O-对甲基二亚苄基-D-甘露醇(VI)属于新化合物未见有文献报道.4种新型的手性二醇应用于查尔酮的不对称环氧化均显示了较高的催化活性(97.4%-100%conv.)和中等或偏低的对映选择性(14%-31.7?).

APPLICATION OF CHIRAL DIOL LIGAND DERIVED FROM D-MANNITOL IN ASYMMETRIC EPOXIDATION REACTION

Chiral diols 1,2,5,6-O-diisopropalene-D-mannitol(III) and 1,3,4,6-O-dibenzaliene-D-mannitol(IV) and its derivatives were synthesized and characterized,among which 1,3,4,6-O-di(p-chlorobenzaliene)-D-mannitol(V) and1,3,4,6-O-di(p-methyl benzaliene)-D-mannitol(VI) are new compounds.When these chiral diol ligand were tested in asymmetric epoxidation of chalcone and cinnamyl alcohols,they all gave good catalytic activity(97.4%-100%conv.),and low to moderate enantioselectivity(14%-31.7?).The relative small rigidity of the backbone of the ligands may accounts for these results. When they were tested in the asymmetric epoxidation cinnalmyl alchhol,moderate enantioselectivity(26.75%-33.96?)were also obtained probably for deficiency of carbonyl to coordinate with the central metal.