Vachal P, Jacobsen E N
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Org Lett. 2000 Mar 23;2(6):867-70. doi: 10.1021/ol005636+.
[formula: see text] Highly enantioselective addition of HCN to ketoimines has been achieved for the first time using readily accessible and recyclable Schiff base catalysts. Essentially quantitative isolated yield and enantioselectivity of up to 95% ee was obtained. Furthermore, some of the Strecker adducts could be recrystallized in high recovery, yielding optically pure materials. Conversion of the alpha-aminonitrile adducts to the corresponding alpha-quaternary alpha-amino acids was effected in high yield by a formylation/hydrolysis sequence.
[化学式：见正文]首次使用易于获得且可循环利用的席夫碱催化剂实现了HCN对酮亚胺的高度对映选择性加成。获得了基本上定量的分离产率以及高达95% ee的对映选择性。此外，一些斯特雷克加成物能够以高回收率重结晶，得到光学纯的物质。通过甲酰化/水解序列，α-氨基腈加成物以高产率转化为相应的α-季铵化α-氨基酸。
