1579291-77-2Relevant academic research and scientific papers
Control of the Chemoselectivity of Metal N-Aryl Nitrene Reactivity: C-H Bond Amination versus Electrocyclization
Kong, Chen,Jana, Navendu,Jones, Crystalann,Driver, Tom G.
, p. 13271 - 13280 (2016/10/22)
A mechanism study to identify the elements that control the chemoselectivity of metal-catalyzed N-atom transfer reactions of styryl azides is presented. Our studies show that the proclivity of the metal N-aryl nitrene to participate in sp3-C-H bond amination or electrocyclization reactions can be controlled by either the substrate or the catalyst. Electrocyclization is favored for mono-β-substituted and sterically noncongested styryl azides, whereas sp3-C-H bond amination through an H-atom abstraction-radical recombination mechanism is preferred when a tertiary allylic reaction center is present. Even when a weakened allylic C-H bond is present, our data suggest that the indole is still formed through an electrocyclization instead of a common allyl radical intermediate. The site selectivity of metal N-aryl nitrenes was found to be controlled by the choice of catalyst: Ir(I)-alkene complexes trigger electrocyclization processes while Fe(III) porphyrin complexes catalyze sp3-C-H bond amination in substrates where Rh2(II) carboxylate catalysts provide both products.
Rh2(II)-catalyzed ester migration to afford 3 H-indoles from trisubstituted styryl azides
Kong, Chen,Driver, Tom G.
, p. 802 - 805 (2015/04/27)
Rh2(II)-Complexes trigger the formation of 3H-indoles from ortho-alkenyl substituted aryl azides. This reaction occurs through a 4π-electron-5-atom electrocyclization of the rhodium N-aryl nitrene followed by a [1,2]-migration to afford only 3H-indoles. The selectivity of the migration is dependent on the identity of the β-styryl substituent.
Development of a Suzuki cross-coupling reaction between 2-azidoarylboronic pinacolate esters and vinyl triflates to enable the synthesis of [2,3]-fused indole heterocycles
Jana, Navendu,Nguyen, Quyen,Driver, Tom G.
, p. 2781 - 2791 (2014/04/17)
The scope and limitations of a Suzuki reaction between 2-azidoarylboronic acid pinacolate esters and vinyl triflates are reported. This cross-coupling reaction enables the regioselective synthesis of indoles after a subsequent RhII2-catalyzed sp2-C-H bond amination reaction.
Efficient synthesis of 3 H-indoles enabled by the lead-mediated α-arylation of β-ketoesters or γ-lactams using aryl azides
Zhou, Fei,Driver, Tom G.
, p. 2916 - 2919 (2014/06/23)
The development of a lead-mediated α-arylation reaction between aryl azides and β-ketoesters or γ-lactams that facilitates the formation of 3H-indoles is disclosed. Twenty-five examples are included which demonstrate the generality of this reaction to access aryl azides bearing tetrasubstituted o-alkyl substituents. When paired with a Staudinger reduction, this reaction streamlines the synthesis of functionalized 3H-indoles.
