A Dinickel Catalyzed Cyclopropanation without the Formation of a Metal Carbene Intermediate
作者:Arnab K. Maity、Annah E. Kalb、Matthias Zeller、Christopher Uyeda
DOI:10.1002/anie.202011602
日期:2021.1.25
Mechanistic studies reveal that a metal carbene intermediate is not part of the catalytic cycle. The (NDI)Ni2(CHSiMe3) complex was independently synthesized and found to be unreactive toward dienes. Based on DFT models, we propose an alternative mechanism that begins with a Ni2‐mediated coupling of (Me3Si)CHN2 and the diene. N2 extrusion followed by radical C−C bond formation generates the cyclopropane product
The endoperoxides were dihydroxylated and protected to provide a series of endoperoxide buildingblocks for organic synthesis, with potential use as precursors for the synthesis of branched azasugars. Preliminary exploration of the chemistry of these buildingblocks provided access to a variety of derivatives including tetrahydrofurans, epoxides and protected amino-tetraols.