Gold- and Iodine-Mediated Internal Oxygen Transfer of Nitrone- and Sulfoxide-Functionalized Alkynes
作者:Dan Chen、Guoyong Song、Aiqun Jia、Xingwei Li
DOI:10.1021/jo201347r
日期:2011.10.21
Intramolecular oxygen transfer of nitrone- and sulfoxide-alkynes was achieved using a catalytic amount of Au(I) and a stoichiometric amount of iodine. The Au(I)-catalyzed cyclization of a nitrone-terminal alkyne afforded a cyclic iminoester, while cyclization of analogous nitrone-internal alkynes yielded aldehyde enones. The I-2-mediated cyclization of nitrone-alkynes afforded iodinated gamma-lactams and the I-2-mediated internal redox of the closely related sulfoxide alkynes gave diketones functionalized with a thoiether.
Isolation of Azomethine Ylides and Their Complexes: Iridium(III)-Mediated Cyclization of Nitrone Substrates Containing Alkynes
作者:Guoyong Song、Dan Chen、Yan Su、Keli Han、Cheng-Ling Pan、Aiqun Jia、Xingwei Li
DOI:10.1002/anie.201102561
日期:2011.8.16
Cat. at rest: [IrCp*Cl2}2] readily catalyzes the redox cyclization of nitron alkynes (e.g., 1) to give azomethineylides that can then react with electrophiles and π bonds. The unusual O‐bound azomethinecomplex 2 was isolated and identified as the resting state of the catalyst in the azomethineylide formation. Cp*=C5Me5.
猫。静止时:[IrCp * Cl 2 } 2 ]容易催化硝酮炔烃(例如1)的氧化还原环化反应,从而生成可与亲电子试剂和π键反应的偶氮甲亚胺。分离出异常的O结合的偶氮甲碱络合物2,并将其确定为偶氮甲碱叶立德形成中催化剂的静止状态。Cp * = C 5 Me 5。