Nickel-Catalyzed Regio- and Stereoselective Reductive Coupling between Methylenecyclopropanes, Aldehydes, and Triethylborane with Retention of the Cyclopropane Ring
Running rings: The first regio‐ and stereoselective reductive coupling between methylenecyclopropanes, aldehydes, and triethylborane with retention of the cyclopropanering was achieved using a nickel–phosphine catalyst (see scheme). The reductive coupling reaction constructed a stereo‐defined cyclopropanering with formation of a quaternary stereogenic carbon center.