Gold-Catalyzed Nitrene Transfer from Benzofuroxans to <i>N</i>-Allylynamides: Synthesis of 3-Azabicyclo[3.1.0]hexanes
Nikolay V. Shcherbakov, Dmitry Dar’in, Vadim Yu. Kukushkin, Alexey Yu. Dubovtsev
Abstract
The gold-catalyzed reaction between benzofuroxans, functioning as nitrene transfer reagents, and N-allylynamides leads to 3-azabicyclo[3.1.0]hexan-2-imines. This highly selective annulation proceeds smoothly under mild conditions (5 mol % Ph3PAuNTf2, PhCl, 60 °C) and exhibits high functional group tolerance (21 examples, ≤96% yields). The obtained cyclopropanated products represent a useful synthetic platform with an easily modulated substitution pattern as illustrated by their postmodifications. Intramolecular cyclopropanation of gold α-imino carbene intermediates is suggested as a key step of the catalytic cycle.
Topics & Concepts
NitreneCyclopropanationIntramolecular forceCatalysisCarbeneAnnulationChemistryReagentCombinatorial chemistryMedicinal chemistryFunctional groupCatalytic cycleStereochemistryOrganic chemistryPolymerCatalytic Alkyne ReactionsCyclopropane Reaction MechanismsSynthetic Organic Chemistry Methods