Study On Cyanation And Trifluoromethylation Reaction Via C-C Bond Forming

The cyano-contained compounds widely exist in the natural produts, are importantbuilding blocks in pharmaceuticals, agricultural chemicals and fine chemicals as result ofdiverse transformations in organic synthesis. Meanwhile fluorinated chemicals have attractedincreasing interests in the fields of pharmaceuticals, agrochemicals, and materials. So newmethods were developed to introduce cyano-group and trifluoromethyl group into molecularsvia C-C bond forming.Reaction parameters including cyanating reagents, catalyst structures, solvent, cations,additives and concentration were extensively studied in terms of enantioselectivity and yield.And the highly efficient asymmetric conjugate hydrocyanation of aromatic enones withbenzophenone cyanohydrin has been achieved by an anionic chiral phosphate catalyst. Using5-10mol%of catalyst in situ generated from (S)-6,6’-di(1-adamantyl)-1,1’-binaphthyl-2,2’-diylphosphate and NaNH2,5-10mol%of2-tert-butylphenol as the additive, high yields (72-96%) and excellent enantioselectivities (92-98%ee) were achieved within2h in toluene at80C.19examples of β-cyano ketones with highly optical purity were obtained, includingone new compound. Compared to the literature methods, this transformation could beaccomplished without any noble metals, at low catalyst loading and in a short reaction time.This protocol may open a new methodology to associate nucleophiles in the context of H-bonding using chiral anion catalyst.A direct electrophilic-cyanation of β-keto esters and amides was developed with1-Cyano-1,2-benziodoxol-3(1H)-one (C1). This new cyano cation (CN+) equivalent was usedas electrophilic cyanating agent for the first time. And this cyano hypervalent iodine(III)-CNwas synthsized in high yield with a short time by a modified literature method. Theelectrophilic-cyanation was accomplished within10min without any catalyst and base inDMF at room temperature. Thus,17examples of highly functionalized quaternary carbon-centered nitriles were produced in high to excellent yields, including16new compounds.The simple, mild and efficient condition affords an opportunity to develop the catalyticasymmetric-cyanation.A radical trifluoromethylarylation of active alkenes was established through a tandem radical addition and C-H activation pathway using N-arylacrylamides as substrates and insitu generated [AgCF3] species from Me3SiCF3and AgF as trifluoromethyl radical precursor.It provided a concise method to prepare21examples of CF3-containing oxindoles within4h, including8new compounds. The transformation could be finished in a short time withoutexpensive Togni′s reagent. The excellent regioselectivity was demonstrated when a meta-substituted N-arylacrylamide was used.