elusive substrates (e.g., an unactivatedolefin, 1-octene). Comprehensive mechanistic studies on the electronic effect, deuterium exchange, kinetic isotope effect, kinetic profile, and numerous Rh(III) complexes have established [RhCp*](2+) as the catalyst resting state, electrophilic C-H activation as the turnover-limiting step, and a five-membered rhodacycle as a catalytically competent intermediate.
Rhodium-catalyzed tandem acylmethylation/annulation of <i>N</i>-nitrosoanilines with sulfoxonium ylides for the synthesis of substituted indazole <i>N</i>-oxides
作者:Xin-Feng Cui、Guo-Sheng Huang
DOI:10.1039/d0ob00723d
日期:——
ylides through the rhodium(III)-catalyzed C–H activation and cyclization reaction is described here. This protocol employs nitroso as a traceless directing group. The transformation features powerful reactivity, tolerates various functional groups, and proceeds with moderate to good yields under an ambient atmosphere, providing a straightforward approach to access structurally diverse and valuable indazole
C–H Activation-Based Traceless Synthesis via Electrophilic Removal of a Directing Group. Rhodium(III)-Catalyzed Entry into Indoles from <i>N</i>-Nitroso and α-Diazo-β-keto Compounds
A distinct C–H activation-based traceless synthetic protocol viaelectrophilic removal of a directing group is reported, complementing the currently exclusively used nucleophilic strategy. Rh(III)-catalyzed, N-nitroso-directed C–H activation allows the development of a traceless, atom- and step-economic, cascade approach for the synthesis of indole skeletons, starting from readily available N-nitroso
cobalt(III)-catalyzed cross-coupling/cyclization of aryl C–H bonds of N-nitrosoanilines with α-diazo-β-ketoesters has been achieved. This protocol features a unique combination of Csp2-H activation/Wolffrearrangement process, allowing for the rapid assembly of quaternary 2-oxindoles. The empirical evidence and density functional theory (DFT) calculations reveal the trapping process of transient acceptor ketene
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