Regioselective C–H chalcogenylation and halogenation of arenes and alkenes under metal-free conditions

Abstract

The reactions of direct Csp2–H chalcogenylation and halogenation of N-arylpyrrolidone under the action of PIFA without a directing group and under metal-free conditions were reported in this paper.

Selenium Modification of Natural Products and Its Research Progress

“…Therefore, how to efficiently form selective C-Se bonds is crucial for the synthesis of cyclic selenides. The use of transition metals to catalyze the cross-coupling of boronic acid aryl/halogenated aromatics with selenium sources is a common method for selenizing cyclic compounds [71]. Cross-coupling reactions usually use transition metals such as ruthenium, silver, and copper as catalysts.…”

I2 or I2/PIFA one-pot induced system for rapid synthesis of chalcogenated enamides, uracils or 2-pyridones under mild conditions

“…19 Finally, He and Liu documented the regioselective C–H chalcogenation of N -phenyl-pyrrolidones and piperidone at the C-4 position of the phenyl ring using phenyliodine( iii ) bis(trifluoroacetate) (PIFA) as an oxidant along with diphenyl selenium ether or its sulfur counterpart in dichloromethane at 30–60 °C. 20 Notably, they reported a sole example of the selenation of 1-vinylpyrrolidin-2-one, a readily available exo -enamide substrate, yielding the corresponding ( E )-(phenylselanyl) product in a modest 19% yield (Scheme 1d, eqn (3)). Continuing our interest in advancing original methodologies with a focus on selective and atom-economic reactions for synthesizing small yet intricate nitrogen-containing molecules of biological significance, we set out to achieve direct C–Se and C–S coupling of enamides and their analogues.…”