Radical coupling of β-ketoesters and amides promoted by Brønsted/Lewis acids

Modular Synthesis of Polysubstituted Quinolin-3-amines by Oxidative Cyclization of 2-(2-Isocyanophenyl)acetonitriles with Organoboron Reagents

“…Unfortunately, the sequential additions of aryl and alkyl radicals to 2-(2-isocyanophenyl)­acetonitriles have not been investigated to date in contrast to FG-arylisonitriles . The radical cascade cyclization of 2-(2-isocyanophenyl)­acetonitriles can break through the restrictions mentioned above by introducing aryl and alkyl groups along with the construction of quinoline skeletons and amine motifs, aryl radicals, and alkyl that can be generated from the corresponding aryl- or alkylborons upon suitable oxidations . As part of our ongoing interests in organoboron chemistry and being inspired by our previous works on isocyanides ,, and the works of Studer, Nagib, Chatani, and Lei, we envisioned that with 2-(2-isocyanophenyl)­acetonitrile as a radical acceptor and organoboron as a radical donor, an intermolecular radical addition to isocyanide would lead to an imidoyl radical, which could subsequently intramolecularly attack the cyanide group in 2-(2-isocyanophenyl)­acetonitrile to render the desired quinolin-3-amines.…”

TfOH-Catalyzed Cascade C–H Activation/Lactonization of Phenols with α-Aryl-α-diazoesters: Rapid Access to α-Aryl Benzofuranones

“…To test the feasibility of the cascade C–H activation/lactonization of α-aryl-α-diazoacetates (Table ), p -cresol 2a was reacted with methyl α-phenyl-α-diazoacetate 1a in dichloromethane (DCM) using TsOH as a catalyst (10% mol) (entry 1). Gratifyingly, the methyl α-phenyl benzofuranone 3aa was obtained in 27% isolated yield.…”

Electrochemically driven α-thiocarbamylation via a dehydrocoupling strategy of β-ketoesters with amines and CS2

“…In view of the above concepts and our experience in the electrochemical synthesis of organosulfur compounds, 10 in particular our continuing interest in C–S bond forming reactions and chemical transformations of β-ketoesters, 11 we report herein an electrochemical dehydrocoupling reaction in which CS 2 and amines undergo a multicomponent reaction with β-ketoesters (C-centered nucleophiles) under mild conditions for the one-pot synthesis of carbonyl thiocarbamates in the presence of NaO t Bu as a base (Scheme 1c).…”