Intramolecular Phosphine-Promoted Knoevenagel Based Redox-Reaction

A Knoevenagel based redox-reaction promoted by intramolecular phosphine sources is presented for the first time. The influence of different diketones, aldehydes, bases and acids was investigated. The effects of different substituents were evaluated based on their electronical influence on the diketone structure. With the obtained results a mechanism is proposed, giving information about transition states formed during the reaction, which can lead to different products. This type of an internal redox transformation with a phosphine oxide moiety remaining in the molecule after the redox reaction represents a new type of reaction.

Two-Step Construction of Thiophene-Oxazole Dyads with Fluorescent Properties by the Ring Expansion of Aziridines

A general approach toward 2-thiophenylsubstituted oxazoles using aziridination of a double bond of (acyl)alkenyl thiophenes with the subsequent expansion of the aziridine ring is developed. The isolation of intermediate aziridine is not necessary. This expedient protocol covers a broad scope of readily available 2-, 3-, and benzothiophene derivatives, is practical and reliable, requires short reaction times, and is simple to set up and work up reaction mixtures. Thiophenyloxazoles, obtained by this method, exhibit fluorescence with high quantum yields.

C-H bond halogenation catalyzed or mediated by copper: an overview

Carbon-halogen (C-X) bonds are amongst the most fundamental groups in organic synthesis, they are frequently and widely employed in the synthesis of numerous organic products. The generation of a C-X bond, therefore, constitutes an issue of universal interest. Herein, the research advances on the copper-catalyzed and mediated C-X (X = F, Cl, Br, I) bond formation via direct C-H bond transformation is reviewed.

CuO/I2-mediated intramolecular annulation for the synthesis of 2-aroyl-3-hydroxy-4-iodonaphthalenes

A novel method for the direct synthesis of 2-aroyl-3-hydroxy-4-iodonaphthalenes has been developed via CuO/I₂-mediated domino reactions.

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.

Efficient approach to 2-hydroxy-2,3-dihydrofuran derivatives and its application for the synthesis of novel 4-(1H-pyrazol-4-yl)pyridazines

A highly efficient method for the synthesis of 2-hydroxy-2,3-dihydrofuran derivatives from 1,4-enediones and phenacyl pyridinium halides via a domino reaction has been developed. At the same time, we also synthesize the novel 4-(1H-pyrazol-4-yl)pyridazine skeleton.