One-pot synthesis of functionalized bis(trifluoromethylated)benziodoxoles from iodine(I) precursors.

Bis(trifluoromethylated)benziodoxoles (Bx) are broadly used cyclic hypervalent iodine reagents due to their stability and unique chemical properties. However, current methods to access them require several steps and long reaction times, making their synthesis tedious. Herein, a direct one-pot synthesis of bis(trifluoromethylated) Bx reagents from iodine(I) precursors is reported, enabling the synthesis of functionalized reagents.

Copper (I)-BOX Catalyzed Asymmetric 3-Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines.

An asymmetric 3-component reaction between EthynylBenziodoXoles (EBXs), 2,2,2-trifluorodiazoethane and nucleophiles catalyzed by a Cu -BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and anilines, which are valuable building blocks in synthetic and medicinal chemistry. The reaction proceeds with high enantioselectivity and yield with different nucleophiles such as primary, secondary and tertiary alcohols, as well as both electron-rich and electron-poor anilines.

Cu(I)-Catalyzed -Aminoalkynylation of Diazo Compounds: Synthesis of Fluorinated Propargylic Amines.

The -aminoalkynylation of fluorinated diazo compounds catalyzed by a simple Cu(I) salt is described. This three-component reaction allows the synthesis of propargylic amines with broad functional group tolerance. Both electron-rich and electron-poor anilines can be used as nucleophiles and alkyl-, aryl-, and silyl-substituted EthynylBenziodoXoles (EBX) as electrophiles.

Decarboxylative Cyanation of Aliphatic Carboxylic Acids via Visible-Light Flavin Photocatalysis.

An operationally simple method is disclosed for the decarboxylative cyanation of aliphatic carboxylic acids at room temperature. Riboflavin tetraacetate, which is an inexpensive organic photocatalyst, promotes the oxidation of carboxylic acids upon visible-light activation. After decarboxylation, the generated radicals are trapped by TsCN, yielding the desired nitriles without any further additive, in a redox-neutral process.

A photoredox-neutral Smiles rearrangement of 2-aryloxybenzoic acids.

We report on the use of visible light photoredox catalysis for the radical Smiles rearrangement of 2-aryloxybenzoic acids to obtain aryl salicylates. The method is free of noble metals and operationally simple and the reaction can be run under mild batch or flow conditions. Being a redox neutral process, no stoichiometric oxidants or reductants are needed.

Photocatalytic Dehydrogenative Lactonization of 2-Arylbenzoic Acids.

A metal-free dehydrogenative lactonization of 2-arylbenzoic acids at room temperature was developed. This work illustrates the first application of visible-light photoredox catalysis in the preparation of benzo-3,4-coumarins, an important structural motif in bioactive molecules. The combination of photocatalyst [Acr(+)-Mes] with (NH4)2S2O8 as a terminal oxidant provides an economical and environmentally benign entry to different substituted benzocoumarins.