手性联萘基-2,2'-联吡啶及其衍生物的合成及其在不对称合成中的应用

利用Kröhnke方法,以芳基乙酮为原料一锅法简洁地合成了6-芳基-6'-溴-2,2'-联吡啶2b~2d。 通过(R)-3-(4,4,5,5-四甲基-1,3,2-二噁唑硼烷基)-2,2'-乙氧基-1,1'-联萘((R)-1)与6-溴-2,2'-联吡啶及其衍生物2a~2d的Suzuki偶联, 合成了4种手性6-3-((R)-2,2'-二乙氧基-1,1'-联萘)基]-2,2'-联吡啶(R)-3a~3d。 将配体(R)-3a~3d应用于苯乙酮的不对称氢转移反应中,配体(R)-3a给出92%的转化率和4%的对映体过量(ee)值。

Synthesis of Chiral Binaphthyl 2,2'-Bipydine and Its Derivatives and Their Application to Asymmetric Synthesis

6-Aryl-6'-bromo-2,2'-bipyridine derivatives 2b~2d were synthesized efficiently from aryl-ethanone by the Kröhnke method in one-pot. Then, four chiral 6-3-((R)-2,2'-diethoxyl-1,1'-binaphthyl)]-2,2'-bipyridine ligands (R)-3a~3d were synthesized by Suzuki coupling of (R)-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolanyl)-2,2' -diethoxyl-1,1'-binaphthyl (R)-1 with 6-bromo-2,2'-bipyridine derivatives 2a~2d. These ligands were applied to asymmetric transfer hydrogenation of acetophenone. The ligand (R)-3a affords 92% of conversion and 4% enantiomeric excess(ee).