Chan K F, Wong H N
Department of Chemistry and Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China.
Org Lett. 2001 Dec 13;3(25):3991-4. doi: 10.1021/ol010196n.
[reaction: see text] The addition reactions of various nucleophiles to a furyl aldehyde bearing a chiral boronate at the C-3 position furnished chromatographically separable diastereomers. The R diastereoselection was more favorable when no additive was added. Surprisingly, when lithium alkoxides were selected as additives, the S diastereoselection is superior instead. Further transformation of C-B bonds to C-C bonds was achieved by using standard Suzuki coupling conditions to give optically active 2,3-disubstituted furyl alcohols.
[反应：见正文] 各种亲核试剂与在C-3位带有手性硼酸酯的呋喃醛的加成反应产生了可通过色谱分离的非对映异构体。当不添加添加剂时，R非对映选择性更有利。令人惊讶的是，当选择醇锂作为添加剂时，S非对映选择性反而更优。通过使用标准的铃木偶联条件，实现了C-B键到C-C键的进一步转化，得到了光学活性的2,3-二取代呋喃醇。
