NIS-Catalyzed Reactions: Amidation of Acetophenones and Oxidative Amination of Propiophenones

Chemo- and Stereoselective Transition-Metal-Free Amination of Amides with Azides

The synthesis of α-amino carbonyl/carboxyl compounds is a contemporary challenge in organic synthesis. Herein, we present a stereoselective α-amination of amides employing simple azides that proceeds under mild conditions with release of nitrogen gas. The amide is used as the limiting reagent, and through simple variation of the azide pattern, various differently substituted aminated products can be obtained. The reaction is fully chemoselective for amides even in the presence of esters or ketones and lends itself to preparation of optically enriched products.

Spontaneous Oxygenation of Siloxy-N-silylketenimines to α-Ketoamides

Siloxy-N-silylketenimines generated in situ from O-silyl cyanohydrins were converted to α-ketoamides by brief exposure to air or oxygen. Oxidation under extremely mild conditions can be explained by assuming the intermediacy of a 3-imino-1,2-dioxetane derivative generated via triplet-singlet intersystem crossing after the reaction of siloxy-N-silylketenimines with triplet oxygen.

N-Bromosuccinimide promoted and base switchable one pot synthesis of α-imido and α-amino ketones from styrenes

An N-Bromosuccinimide (NBS) promoted one pot strategy for the synthesis of α-amino functionalized aryl ketones starting from commercially available styrenes has been developed.

Copper–TEMPO-catalyzed synthesis of α-ketoamides via tandem sp3C–H aerobic oxidation and amination of phenethyl alcohol derivatives

The first synthesis of α-ketoamides from phenethyl alcohol derivatives, simple and readily available substrates, was achieved.

A two-step continuous synthesis of α-ketoamides and α-amino ketones from 2° benzylic alcohols using hydrogen peroxide as an economic and benign oxidant

A practical two-step flow synthesis of α-ketoamides and α-amino ketones via direct oxidative coupling between 2° benzylic alcohols and amines was developed.

Metal-free oxidative esterification of acetophenones with alcohols: a facile one-pot approach to α-ketoesters

A novel oxidative esterification method for the synthesis of α-ketoesters has been developed, which is a facile one-pot approach to α-ketoesters from acetophenones with alcohols, especially under metal-free conditions with broad substrate scope.

Transition metal-free synthesis of α-ketoamides from arylmethyl ketones and alkylphosphoramides

Synthesis of α-ketoamides from arylmethyl ketones and hexalkylphosphoramides using TBAI as the catalyst and TBHP as the oxidant.

I2-promoted aerobic oxidative coupling of acetophenes with amines under metal-free conditions: facile access to α-ketoamides

A novel and efficient I₂-promoted oxidative coupling of acetophenes with amines to α-ketoamides is presented, which employs molecular oxygen as an environmentally friendly oxidant under metal-free conditions.

Synthesis of α-sulfenyl monoketones via a metal-free oxidative cross dehydrogenative coupling (CDC) reaction

α-Sulfenyl ketones are potential precursors which find a variety of applications in organic synthesis.

Brønsted acid mediated N–O bond cleavage for α-amination of ketones through the aromatic nitroso aldol reaction

A Brønsted acid mediated N–O bond cleavage for α-amination of ketones has been developed through the nitroso aldol reaction of less-reactive aromatic nitroso compounds and silyl enol ethers having a disilane (–SiMe₂TMS) backbone.

The Mukaiyama aldol reaction of in situ generated nitrosocarbonyl compounds: selective C-N bond formation and N-O bond cleavage in one-pot for α-amination of ketones

A practical protocol for the α-amination of ketones (up to 99% yield) has been developed via the Mukaiyama aldol reaction of in situ generated nitrosocarbonyl compounds. The reaction with silyl enol ethers having a disilane (-SiMe2TMS) backbone proceeded not only with perfect N-selectivity but concomitant N-O bond cleavage was also accomplished. Such a cascade of C-N bond formation and N-O bond cleavage in a single step was heretofore unknown in the field of nitrosocarbonyl chemistry. A very high diastereoselectivity (dr = 19 : 1) was accomplished using (-)-menthol derived chiral nitrosocarbonyl compounds.

Iodine-catalyzed radical oxidative annulation for the construction of dihydrofurans and indolizines

Through iodine catalysis, the direct oxidative coupling/annulation of β-keto esters or 2-pyridinyl-β-esters with alkenes was achieved. This reaction procedure provides a simple and selective way for the synthesis of dihydrofurans and indolizines in one step.

Formamidine hydrochloride as an amino surrogate: I2-catalyzed oxidative amidation of aryl methyl ketones leading to free (N–H) α-ketoamides

A highly efficient molecular iodine catalyzed oxidative amidation of aryl methyl ketones has been developed. This reaction represents a novel strategy for the synthesis of free (N–H) α-ketoamides.

Iodine promoted α-hydroxylation of ketones

A novel method for α-hydroxylation of ketones using substoichiometric amount of iodine under metal-free conditions is described.

Copper(ii) bromide-catalyzed intramolecular decarboxylative functionalization to form a C(sp3)–O bond for the synthesis of furo[3,2-c]coumarins

Copper(ii) bromide-catalyzed intramolecular decarboxylative functionalization to form a C(sp³)–O bond has been developed.

A chemoselective α-aminoxylation of aryl ketones: a cross dehydrogenative coupling reaction catalysed by Bu4NI

Tetrabutyl ammonium iodide (TBAI) catalyzed α-aminoxylation of ketones using aq. TBHP as an oxidant has been accomplished.

Copper-catalyzed direct α-ketoesterification of propiophenones with acetophenones via C(sp3)–H oxidative cross-coupling

A Cu-catalyzed direct α-ketoesterification of propiophenones with acetophenones via C(sp³)–H oxidative cross-coupling was developed by using O₂ as an oxidant.

Tuning radical reactivity using iodine in oxidative C(sp3)–H/C(sp)–H cross-coupling: an easy way toward the synthesis of furans and indolizines

Molecular iodine was found to be an effective redox catalyst for the oxidative cross-coupling of carbonyl compounds with terminal alkynes.

An iodine(iii) mediated oxidative rearrangement of enamines: efficient synthesis of α-amino ketones

An iodine(iii) mediated chemoselective oxidative rearrangement of β,β-diarylenamines to α-amino ketones has been accomplished with excellent yield.