Asymmetric Lewis Acid Catalyzed Addition of Isocyanides to Aldehydes – Synthesis of 5-Amino-2-(1-hydroxyalkyl)oxazoles
作者:Shixin Wang、Mei-Xiang Wang、De-Xian Wang、Jieping Zhu
DOI:10.1002/ejoc.200700340
日期:2007.8
Stannous chloride efficiently catalyzes condensations between alpha -isocyanoacetamides C==NCHRCOR1 (I, R = H, PhCH2; R1 = N-morpholinyl, Et2N) and a variety of aldehydes to afford the corresponding 5-amino-2-(1-hydroxyalkyl)oxazoles II (R2 = Et, n-C6H13, Me2CH, cyclohexyl, tert-Bu, COOEt, Ph, etc.) in good to excellent yields. The [Sn-(R)-Ph-PyBox](OTf)2-catalyzed reaction between I (R = PhCH2; R1
氯化亚锡有效地催化 α-异氰基乙酰胺 C==NCHRCOR1 (I, R = H, PhCH2; R1 = N-morpholinyl, Et2N) 和多种醛之间的缩合反应,得到相应的 5-amino-2-(1-hydroxyalkyl)恶唑 II(R2 = Et、n-C6H13、Me2CH、环己基、叔丁基、COOEt、Ph 等)的产率非常好。[Sn-(R)-Ph-PyBox](OTf)2-催化的 I(R = PhCH2;R1 = N-吗啉基)和 2-(苄氧基)乙醛之间的反应显示出同质转化效应,最大值为。在-40 度下获得的恶唑 II (R2 = PhCH2OCH2) (80%) 对映体过量。[在 SciFinder (R) 上]