Synthesis of novel C2-symmetric chiral crown ethers and their application to enantioselective trifluoromethylation of aldehydes and ketones
作者:Hiroyuki Kawai、Akihiro Kusuda、Satoshi Mizuta、Shuichi Nakamura、Yasuhiro Funahashi、Hideki Masuda、Norio Shibata
DOI:10.1016/j.jfluchem.2009.06.004
日期:2009.8
Synthesis of novel C2-symmetric chiral crown ethers and their application to enantioselective trifluoromethylation of aldehydes and ketones are discussed. The use of a series of C2-symmetric chiral crown ethers 2 or 3 derived from commercially available (R)-1,1′-bi-2-naphthol for the enantioselective trifluoromethylation of 2-naphthyl aldehyde 1a with (trifluoromethyl)trimethylsilane in the presence
讨论了新型的C2对称手性冠醚的合成及其在醛和酮的对映选择性三氟甲基化中的应用。一系列C2对称的手性冠醚2或3从可商购获得的(R)-1,1'-bi-2-萘酚用于在(N )中用(三氟甲基)三甲基硅烷对2-萘醛1a进行对映选择性三氟甲基化的用途。试图存在一个基地。碘取代的冠醚2b被发现在模型反应中最有效。在21-44%ee中,芳基或烷基醛和烷基芳基酮的三氟甲基化反应均表现出中等对映选择性。尽管ee仍然是可改进的,但这是手性冠醚催化的对映选择性三氟甲基化反应的第一个例子。