A formal [4+2] annulation reaction of phthalaldehyde and 3-ylideneoxindole via a tandem process of Stetter-aldol reaction was accomplished by the application N-heterocyclic carbenes as effective catalysts. Under mild conditions, this unprecedented cascade reaction readily occurs in good yield, enabling straightforward access to assemble functionalized tetrahydronaphthalene-fused spirooxindoles. For the first time, the feasibility for asymmetric Stetter-aldol reaction has also been briefly explored by employing chiral organic bases to promote the asymmetric transformation ..read more

Polyol esters are abundant bio-based resources. Integration of polyol esters into the production chain of fine chemicals would reduce carbon emission and improve the sustainability of the chemical industry. An efficient synthetic route towards phenoxyethanols was developed through catalytic hydroxyethylation of phenols with ethylene glycol diacetate as the reagent. This method showed the potential of ethylene glycol diester as a safe and sustainable substitute for ethylene oxide, a useful but toxic reagent. A variety of phenoxyethanol esters were produced in high yield under simple catalytic c ..read more

An iron(III)-promoted radical fluoroalkylation of o-alkenylaryl isocyanides has been developed using readily available perfluoroalkyl iodides as fluoroalkyl source. This cyclization reaction features broad substrate scope and provides a simple and efficient approach for regioselective construction of biologically important 2-fluoroalkylated quinolines in 38-81% yields ..read more

We report an unprecedented Ni-catalyzed direct monofluoromethylthiolation of acyl chlorides, in situ generated from carboxylic acids, with elemental sulfur (S8) as the S source and fluoroiodomethane (ICH2F) as the CH2F radical source to produce a series of monofluoromethylthioesters in moderate to good yields. This approach features excellent functional group tolerance and broad substrate scope. Additionally, the late-stage monofluoromethylthiolation of complex bioactive molecules can also be accomplished using this method ..read more

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A synthesis of amides from aldehydes promoted by the photoactive complex of Fe2SO4 with 2-picolinic acid, NaCl as chlorine source, Na2S2O8 as a benign oxidant is reported. The reaction is mediated by visible-light and is carried out at room temperature in absence of additives. Fe2SO4 is a readily available earth-abundant metal (EAMs) salt, not needed to be prepared and is environmentally sustainable. Both aliphatic and aromatic aldehydes and mono- and disubstituted amines have been texted in this transformation. This report opens intriguing perspectives for extendeding application of photoacti ..read more

A multicomponent Kröhnke reaction route toward 2-trifluoromethyl pyridines from reaction of chalcones with easily available and stable 1-(3,3,3-trifluoro-2-oxopropyl)pyridin-1-ium bromide and ammonium acetate is reported. The reaction is found to be general with a range of substituted chalcones, and the applicability of the methodology in gram scale is demonstrated. Preliminary results suggest that this transformation is initiated by 1,4-Michael addition, followed by inter- and intramolecular nucleophilic addition, and elimination ..read more

The electrophilic activation of 2H-azirines with triflic anhydride (Tf2O) for an addition/cyclization reaction producing 2-aryl-pyrido[2,3-b]pyrazines regioselectively is described. This reaction proceeds via nucleophilic addition of 3-amino-2-fluoropyridines onto 1-trifloyl-aziridin-2-yl triflates and subsequent cyclization via SNAr. Desulfonylation and oxidation provides a single regioisomer of the aza-bicyclic heterocycle after treatment with Et3N. Optimization of the reaction conditions lead to a range of 2-aryl-pyrido[2,3-b]pyrazines in isolated yields of 20% to 60 ..read more

A sustainable protocol has been devised for the oxidation of activated secondary alcohols to their corresponding carbonyl compounds, as well as their utilization as selective mono-alkylating reagents for both amide and arylsulfonamide derivatives. These reactions proceed smoothly and in good yields (up to 98%) when conducted in Fe-based deep eutectic solvents (DESs), which serve dual roles as solvents and catalysts. Operating under mild (40 °C) and aerobic conditions, these transformations are completed within a 4 h time frame. A pharmacologically relevant amide derivative, specifically a PMRT ..read more

The fluoroalkoxy groups (ORf) are widely used motifs in pharmaceutical and agrochemical fields due to their unique physicochemical properties including higher lipophilicity and increased metabolic stability. Thus, the high value of ORf-containing derivatives has stimulated the development of fluoroalkoxylation reactions. In this review, we highlight the recent progress of various trifluoroalkoxylating reagents and their applications in organic synthesis in the past five years ..read more