carbene bearing a proximal hydroxy group derived from L-pyroglutamic acid was found to be an efficient catalyst for the [3+2] annulation of enals and isatins to give the corresponding spirocyclic oxindolo-gamma-butyrolactones in good yield with good diastereo- and enantioselectivities.
发现带有衍生自
L-焦谷氨酸的近端羟基的手性N-杂环卡宾是有效的催化剂,用于[3 + 2]环烯和
异戊二烯环化反应,从而以高收率得到相应的螺环氧代
吲哚-
γ-丁内酯。良好的非对映和对映选择性。