A highly diastereoselective three-component inverse-electron-demand aza DielsâAlder reaction assisted by per(poly)fluoro-alkanesulfinamides is presented, providing a broad spectrum of highly functionalized piperidine derivatives with excellent endo/exo and facial diastereoselectivities. The electron-withdrawing perfluoroalkyl groups are crucial for the success of this reaction under mild conditions and facilitate monitoring the process and stereoselectivities of the reaction. The synthetic potential of these cycloadducts is also highlighted.
Synthesis of γ-Lactams via Pd(II)-Catalyzed C(sp<sup>3</sup>)–H Olefination Using a Self-Cleaving Polyfluoroethylsulfinyl Directing Group
作者:Nan-Qi Shao、Yu-Hao Chen、Chen Li、Dong-Hui Wang
DOI:10.1021/acs.orglett.0c00326
日期:2020.9.18
A monodentate directinggroup, 2-chlorotetrafluoroethylsulfinylmide (-NHSOCF2CF2Cl), for inert C(sp3)–H bond activation is reported. This directinggroup shows efficient ability in Pd(II)-catalyzed C(sp3)–H olefination. The desired olefination products undergo subsequent Michael addition and in situ expulsion of the auxiliary to provide the free NH γ-lactam products. Preliminary mechanistic studies