Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Angew Chem Int Ed Engl. 2016 Mar 18;55(13):4308-11. doi: 10.1002/anie.201512018. Epub 2016 Feb 23.
A highly diastereoselective method for the synthesis of dihydroepoxybenzofluorenone derivatives from aromatic/vinylic amides and bicyclic alkenes is described. This new transformation proceeds through cobalt-catalyzed C-H activation and intramolecular nucleophilic addition to the amide functional group. Transition-metal-catalyzed C-H activation reactions of secondary amides with alkenes usually lead to [4+2] or [4+1] annulation; to the best of our knowledge, this is the first time that a [3+2] cycloaddition is described in this context. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. Mechanistic studies imply that the C-H bond cleavage may be the rate-limiting step.
描述了一种从芳香族/乙烯基酰胺和环状烯烃合成二氢环氧苯并菲酮衍生物的高非对映选择性方法。这种新的转化通过钴催化的 C-H 活化和酰胺官能团的分子内亲核加成进行。过渡金属催化的二级酰胺与烯烃的 C-H 活化反应通常导致[4+2]或[4+1]环化；据我们所知，这是第一次在这种情况下描述[3+2]环加成。反应在温和的条件下进行，并能耐受广泛的官能团。机理研究表明，C-H 键的断裂可能是速率限制步骤。
