Redox-Neutral and Atom-Economic Route to β-Carbolines via Gold-Catalyzed [4 + 2] Cycloaddition of Indolylynamides and Cyanamides
Nikolay V. Shcherbakov, Elena I. Chikunova, Dmitry Dar’in, Vadim Yu. Kukushkin, Alexey Yu. Dubovtsev
Abstract
Gold(I)-catalyzed [4 + 2] cycloaddition of indolylynamides and cyanamides (aminonitriles) is an efficient redox-neutral and atom-economic route to diversely substituted 1,3-diamino-β-carbolines. The protocol operates under mild conditions (Ph3PAuNTf2 5 mol %, DCE, 60 °C) with a good tolerance to functional groups (23 examples and yields up to 98%). The obtained β-carboline systems represent a versatile synthetic platform with modifiable substituents for successive functionalizations. Control experiments indicate the crucial role of both the nature of reactants and the identity of employed catalysts in the developed cycloaddition.
Topics & Concepts
CycloadditionRedoxCatalysisAtom (system on chip)Combinatorial chemistryChemistryOrganic chemistryComputer scienceEmbedded systemCatalytic Alkyne ReactionsCatalytic C–H Functionalization MethodsAsymmetric Hydrogenation and Catalysis