We report herein a Rh(III)-catalyzed cyclization of N-nitrosoanilines with alkynes for streamlined synthesis of indoles. The synthetic protocol features a distinct internal oxidant, N-N bond, as a reactive handle for catalyst turnover, as well as a hitherto tantalizingly elusive intermolecular redox-neutral manifold, predicated upon C-H activation, for the formation of a five-membered azaheterocycle
A versatile, traceless C–H activation-based approach for the synthesis of diversified heterocycles is reported. Rh(III)-catalyzed, N-amino-directed C–H alkenylation generates either olefination products or indoles (in situ annulation) in an atom- and step-economic manner at room temperature. The remarkable reactivity endowed by this directing group enables scale-up of the reaction to a 10 g scale at
A previously elusive RuII‐catalyzed N−N bond‐based traceless C−H functionalization strategy is reported. An N‐amino (i.e., hydrazine) group is used for the directed C−H functionalization with either an alkyne or an alkene, affording an indole derivative or olefination product. The synthesis features a broad substrate scope, superior atom and step economy, as well as mild reaction conditions.
Potassium <i>tert</i>-Butoxide-Mediated Condensation Cascade Reaction: Transition Metal-Free Synthesis of Multisubstituted Aryl Indoles and Benzofurans
作者:Pengfei Yang、Weiyan Xu、Rongchao Wang、Min Zhang、Chunsong Xie、Xiaofei Zeng、Min Wang
DOI:10.1021/acs.orglett.9b01093
日期:2019.5.17
tert-butoxide-mediated condensation reactioninvolving a vinyl sulfoxide intermediate. Products are obtained from N- or O-benzyl benzaldehydes using dimethyl sulfoxide as a carbon source. The methodology features a wide functional group tolerance and transition metal-free environment. Preliminary mechanistic studies suggest that the reactioninvolves a tandem aldol reaction/Michaeladdition/dehydrosulfenylation/isomerization