An organocatalytic construction of optically enriched substituted pyran derivatives via amine-catalyzed Michael addition and subsequent enolization/cyclisation has been described starting from electronically poor alkenes. Functionalized pyrans were obtained in high enantioselectivities (up to 96%) and good yields (up to 90%) having three contiguous chiral centers.
从电子性差的烯类开始,通过胺催化的迈克尔加成和随后的烯醇化/环化,有机催化地构建了光学富集的取代
吡喃衍
生物。得到的官能化
吡喃具有较高的对映选择性(高达 96%)和良好的产率(高达 90%),并具有三个连续的手性中心。