4,5-Dioxo-imidazolinium Cation Activation of 1-Acyl-1-carbamoyl Oximes: Access to Cyanoformamides Using Dichloroimidazolidinedione
摘要:
Cyanoformamides are prevalent as versatile building blocks for accessing synthetically useful intermediates and biologically active compounds. The development of a milder, simpler, and more efficient approach to cyanoformamides is nontrivial. Herein, we demonstrate the effectiveness of 4,S-dioxo-imidazolinium cation activation for transforming 1-aryl-1-carbamoyl oximes to cyanoformamides. By making use of the readily available and highly modifiable dichloroimidazolidinediones (DCIDs), this novel method of activation offers reactivity remarkably greater than that of other reported protocols, exhibits a high functional group compatibility with mild conditions, and could be scaled up easily. More than 30 examples are demonstrated with good to excellent yields in short reaction times. This research not only provides a mild and efficient alternative approach to assembling a portfolio of cyanoformamides but also extends the dichloroimidazolidinedione-mediated chemistry to encompass the C-C bond cleavage reaction.
A mild and efficient method for the synthesis of cyanoformamides from N,N-disubstituted aminomalononitriles with CsF as the promoter has been developed. This method features a wide substrate scope and high reaction efficiency, and will facilitate corresponding cyanoformamide-based biological studies and synthetic methodology development.
The B12 derivative, heptamethyl cobyrinate, -mediated electrochemicalsynthesis of cyanoformamides has been developed. Aerobic oxygenation of the carbon-centered radical initiated in situ generation of the reactive acyl chloride intermediate, which led to cyanoformamides in the presence of an amine. This one-pot and scalable synthetic method has been demonstrated with 41 examples up to 94% yields with
nickel/Lewis acid (LA) cooperative catalysis to give beta-cyano-substituted acrylates and acrylamides, respectively, in highly stereoselective and regioselective manners. The resulting adducts serve as versatile synthetic building blocks through chemoselective transformations of the ester, amide, and cyano groups as demonstrated by the synthesis of typical structures of beta-cyano ester, beta-amino