Copper-Catalyzed Highly Enantioselective Cyclopentannulation of Indoles with Donor–Acceptor Cyclopropanes

A highly diastereo-
and enantioselective BOX/Cu­(II)-catalyzed C2,C3-cyclopentannulation
of indoles with donor–acceptor cyclopropanes has been developed
on the basis of asymmetric formal [3 + 2] cycloaddition of indoles.
This reaction provides rapid and facile access to a series of enantioenriched
cyclopenta-fused indoline products and can be further extended to
the construction of tetracyclic pyrroloindolines. The synthetic potential
of the reaction was demonstrated in a four-step synthesis of the core
structure of borreverine.

基于不对称的[3+2]环加成反应，已成功开发出一种高度对映异构选择性和对映选择性的BOX/Cu(II)催化的吲哚与供体-受体环丙烷的C2,C3-环戊烷化反应。此反应能够迅速且简便地获得一系列对映富集的环戊基-稠合吲哚衍生物，并可进一步扩展至四环吡咯吲哚的构建。该反应的合成潜力在硼留维林核心结构的四步合成中得到体现。