以联萘酚和大位阻的金刚烷酰氯为原料,经两步合成了系列新型手性单齿亚磷酸酯配体,并应用于铜催化的二乙基锌对环烯酮的不对称1,4-共轭加成反应.结果表明,产物收率和对映选择性最高分别为95%和61%.配体(S)-(2-(adamantane-1-carboxylic acid)-1,1’-binapthalen-2’-yl)-((S)-1,1’-binaphthalen-2,2’-yl)phosphite[(S,S)-3a]的两个(S)-联萘酚构型是匹配的组合,产物的绝对构型主要由配体中2,2’-二氧膦-1,1’-联萘酚的构型控制.
A series of new bulky monophosphite ligands were synthesized from axially chiral BINOL and highly sterically hindered adamantanecarbonyl chloride.These ligands were applied to the Cu-catalyzed asymmetric 1,4-conjugate addition of diethylzinc to cyclic enones and were found to have moderate enantioselectivities(up to 61% ee).The stereochemically matched combination of(S)-BINOL in ligand(S)-(2-(adamantane-1-carboxylic acid)-1,1'-binapthalen-2'-yl)-((S)-1,1'-binaphthalen-2,2'-yl)phosphite induces a moderate enantioselectivity.The sense of enantioselectivity is mainly controlled by the configuration of the 2,2'-o,o-(1,1'-binaphthyl)-dioxo-phosphite moiety of the ligands.