Rh(II)-Catalyzed Chemoselective Oxidative Amination and Cyclization Cascade of 1‑(Arylethynyl)cycloalkyl)methyl Sulfamates

A Rh­(II)-catalyzed
chemoselective oxidative amination and cyclization
cascade of 1-(arylethynyl)­cyclo­alkyl)­methyl sulfamates
has been presented. For a cyclopropyl or cyclobutyl moiety containing
alkynyl sulfamates, the reactions underwent a metallonitrene-initiated
alkyne oxidation along with cyclopropyl ring expansion or alkoxyl
moiety migration to give cyclobutane-fused or methylene­cyclobutane-containing
heterocycles. In the case of a cyclopentyl or cyclohexyl moiety containing
sulfamate, the reaction underwent a direct C–H bond insertion
event to afford the corresponding nitrogen-containing heterocyclic
product.

本工作报道了二价铑（Rh(II)）催化的1-(芳基乙炔基)环烷基甲基氨磺酸酯的化学选择性氧化胺化与环化级联反应。对于含环丙基或环丁基结构的炔基氨磺酸酯底物，反应经由金属氮宾引发的炔烃氧化过程，同时伴随环丙烷扩环或烷氧基基团迁移，分别生成环丁烷稠合或含亚甲基环丁基的杂环产物。而对于含环戊基或环己基结构的氨磺酸酯底物，反应则通过直接C-H键插入过程，得到相应的含氮杂环产物。