Oxytrifluoromethylthiolation of 2,3‐Allenoates with Trifluoromethanesulfinyl Chloride: A Synthetic Approach to Trifluoromethylthiolated 4‐Oxo‐2(E)‐alkenoates and Furans

Ligand-Controlled Regiodivergent Alkoxycarbonylation of Trifluoromethylthiolated Internal Alkynes

Controlling the regioselectivity for the alkoxycarbonylation of unsymmetric internal alkynes is challenging. Herein, a palladium-catalyzed ligand-controlled regiodivergent alkoxycarbonylation of internal trifluoromethylthiolated alkynes was achieved. A series of α- or β-SCF3 acrylates from the same trifluoromethylthiolated alkyne were obtained with moderate to high yield and regioselectivity.

Deoxygenation of ClSO2CF2COOMe with Triphenylphosphine for the Metal-Free Direct Electrophilic Difluoroalkylthiolation of Various Heterocycles

A direct electrophilic difluoroalkylthiolation reaction of indole derivatives and other electron-rich heterocycles using methyl 2,2-difluoro-2-(chlorsulfonyl)acetate (ClSO₂CF₂COOMe) derived from Chen's reagent (FSO₂CF₂COOMe) is described. The ester group in the product can be further utilized in subsequent versatile transformations. The reactions provide good yields of the corresponding difluoroalkylthiolation products and exhibit high functional group compatibility. It is expected to serve as an alternative and practical protocol for difluoroalkylthiolation of various heterocycles.

Synthesis of Pyrrolidin-5-one-2-carboxamides through Cyclization of N-Substituted-2-alleneamides

The synthesis of pyrrolidin-5-one-2-carboxamides 6a-p has been developed via a one-pot Ugi reaction of allenic acids, primary amines, isocyanides, and aldehydes followed by regioselective cyclization of the resultant N-substituted-2-allenamides with KOt-Bu at room temperature. The cyclization reaction was carried out through a 5-exo-dig approach, which resulted in good yields and high atom-economy under transition-metal-free and mild reaction conditions.

Application of Aromatic Substituted 2,2,2-Trifluoro Diazoethanes in Organic Reactions

Abstract:

This review provides an overview of metal-, nonmetal-, light-, or catalyst free-promoting reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with organic molecules for the synthesis of trifluoromethyl-substituted compounds. Several approaches will be reviewed and divided into (i) copper-, iron-, Trop(BF4)-, B(C6F5)3-, light-, or rhodium-promoted reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with silanes, amines, mercaptans, phosphonates, p-cyanophenol, benzoic acid, diphenylphosphinic acid, boranes and nBu3SnH, (ii) rhodium-catalyzed reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with amides and phenylhydroxylamine, (iii) copper-, rhodium-, silver-, and light-catalyzed reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with alkynes, (iv) palladium-, copper-, rhodium- and iron-catalyzed reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with alkenes, (v) BF3·OEt2-, copper-, tin- or TBAB-catalyzed reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with HF·Py, (difluoroiodo)toluene (p-TolIF2), TMSCF3, AgSCF3, TMSCF2Br or 1,3-dicarbonyl compounds, (vi) palladium-, copper-, gold/silver- or rhodium-catalyzed reactions of aromatic substituted 2,2,2-trifluoro diazoethanes with indoles, benzene compounds or pyridines, and (vii) palladium-catalyzed reaction of aromatic substituted 2,2,2-trifluoro diazoethanes with benzyl or allyl bromides.

Catalytic Electrophilic Thiocarbocyclization of Allenes

An efficient approach via catalytic electrophilic thiocarbocyclization of allenes to construct indene-based sulfides with excellent regioselectivities is disclosed. The reactions were carried out at low temperatures by selenide catalysis in the presence of TMSOTf. Not only electrophilic arylthio reagents but also electrophilic alkylthio reagents worked well under these conditions. Furthermore, the method could be applied to intermolecular azidothiolation of allenes.