a mixture of enamines and α-bromoketones, with a catalytic amount of Ir(ppy)3 by visible light (λ = 450 nm), enables the production of various 2,5-diaryl-substituted pyrroles in good to excellent yields. The key intermediates in this reaction have been identified as alkyl radicals, generated from single-electron transfer from the photoexcited Ir(ppy)3* to α-bromoketones, which subsequently react
The mixtures of axiallychiral (aR,S)- and (aS,S)-biscarboline alcohols were firstly used as catalysts in enantioselective 1,2- and 1,4-transfer hydrogenations of ketimines and β-enamino esters, respectively. This mixed axiallychiral catalysts exhibited excellent enantioselectivity (up to 98%ee) in the transfer hydrogenations under mild reaction conditions.
light irradiation of catalytic amount of Ir(ppy)3 at room temperature, a number of N-arylenamines were transformed to their corresponding indoline products in good to excellent yields without requiring any extra additives. This is the first example to synthesize indolines via intramolecular cyclization of enamines under visible light irradiation.
An Oxidant-Free Strategy for Indole Synthesis via Intramolecular C–C Bond Construction under Visible Light Irradiation: Cross-Coupling Hydrogen Evolution Reaction
We describe here an oxidant-free strategy to synthesize indoles, i.e., under visible-light irradiation (λ = 450 nm), catalytic amounts of an iridium(III) photosensitizer and cobaloxime catalyst transform various N-arylenamines exclusively into indoles. Our methodology affords indoles in good to excellent yields under mild reaction conditions and produces H2 as the only byproduct. Spectroscopic and
The construction of substituted indole skeletons is always an important concern of synthetic chemists because of its prevalent structure found in natural products and biological molecules. Here, we succeeded in preparing indoles and their derivativesfrom a wide variety of simple enamines viaradical cyclization only with catalytic amounts of an iridium(III) photosensitizer (PS) in DMSO solution under