Potassium Iodide/ Tert -Butyl Hydroperoxide Mediated Sequential Oxidative Amidation of Ethylarenes - A Direct Approach to α-Ketoamides and Amides

Atmospheric Oxygen Facilitated Oxidative Amidation to α-Ketoamides and Unusual One Carbon Degradative Amidation to N-Alkyl Amides

A mild, transition-metal-free novel synthetic approach for the construction of C═O and C-N bonds has been demonstrated. Easily accessible gem-dibromoalkenes under similar conditions form oxidative amidation product α-ketoamides and unusual degradative amidation product N-alkyl amides by simply changing the amine substitute. Atmospheric air containing molecular oxygen proved to be an ideal oxidant for an amidation reaction. Under similar conditions, the electron-deficient gem-dibromoalkenes play a dual role with different formamides forming novel oxidative amidation products and by the state of art neighboring group participation of amine to unusual one-carbon degradative amidation products.

Copper-Catalyzed Transamidation of Unactivated Secondary Amides via C-H and C-N Bond Simultaneous Activations

Here, we demonstrate that α-C-H and C-N bonds of unactivated secondary amides can be activated simultaneously by the copper catalyst to synthesize α-ketoamides or α-ketoesters in one step, which is a challenging and underdeveloped transformation. Using copper as a catalyst and air as an oxidant, the reaction is compatible with a broad range of acetoamides, amines, and alcohols. The preliminary mechanism studies and density functional theory calculation indicated that the reaction process may undergo first radical α-oxygenation and then transamidation with the help of the resonant six-membered N,O-chelation and molecular oxygen plays a role as an initiator to trigger the transamidation process. The combination of chelation assistance and dioxygen selective oxygenation strategy would substantially extend the modern mild synthetic amide cleavage toolbox, and we envision that this broadly applicable method will be of great interest in the biopharmaceutical industry, synthetic chemistry, and agrochemical industry.

I2-DMSO mediated oxidative amidation of methyl ketones with anthranils for the synthesis of α-ketoamides

An I₂-DMSO mediated oxidative amidation of methyl ketones using anthranils as masked N-nucleophiles has been developed for the direct synthesis of α-ketoamides with high atom-economy. This metal-free process involves reductive N-O bond cleavage of anthranils and oxidative C-N bond formation of methyl ketones under mild conditions. The iodo group and electrophilic formyl group provide multiple possibilities for further functionalization of α-ketoamides.

NaI/KI/NH4I and TBHP as powerful oxidation systems: use in the formation of various chemical bonds

In modern organic synthesis, the execution of reactions in the absence of expensive transition metals has received significant attention from the view-point of green chemistry and sustainable development. As a consequence, the combination of MI-TBHP as an oxidation system (M = Na, K, NH4) has opened a new avenue with significant impact for the succinct synthesis of complex heterocycle molecules via the construction of various chemical bonds [C-X (X = C, N, S, O), N-X (X = N, P) and S-N]. This comprehensive review article delineates the progress of recent developments in this emerging area, with an in-depth discussion on the substrate scope, limitations and proper mechanistic underpinnings. We hope this review will highlight the great potential of this MI-TBHP as a powerful oxidation system and inspire researchers to conduct further endeavors in this domain.

Csp–Csp bond cleavage and fragment coupling: a transition metal-free “extrusion and recombination” approach towards synthesis of 1,2-diketones

A metal-free strategy for C–C bond activation of 1,3-diynes has been established via an “extrusion and recombination” approach to derive structurally important 1,2-diketones in good yields with excellent selectivity.