Study On Phenyliodonium Diacetate Mediated Transformation C=C Bond To C≡N Bond

Alkenes, which are easily accessible from petroleum and renewable resourcessuch as seed oil, are important building blocks in organic synthesis and are utilizedbroadly as starting materials. The transformation of alkenes has occupied importantpositions in organic chemistry. Numerous reactions of alkenes, such as, olefinmetathesis, epoxidation, Wacker oxidation, ozonolysis, etc., have been developed andapplied in a variety of fields including polymer chemistry, organic synthesis,biochemistry, and green chemistry.The transformation of C=C bonds generally result four types of style, that is, C-Csingle bonds, new C=C bonds, C=O bonds and C≡N bonds. While successful for thetransformation C=C bonds to C-C single bonds, new C=C bonds, and C=O bonds, thetransformation C=C bonds to C≡N bonds is much underdeveloped. Suchtransformation is of great value, for it opens a door for the preparation of industriallynitriles from simple and readily available hydrocarbons. On the other hand, it is verydifficult to convert C=C bonds to C≡N bonds. Therefore, the development of newmethods for this transformation is of great value but challenging.Herein, we report a metal-free PhI(OAc)2mediated nitrogenation of alkenesthrough C=C bond cleavage using inorganic ammonia salt as nitrogen source undermild condition, which illustrates a convenient method toward the synthesis of nitrilesfrom readily available starting materials.The main contents of the article include:(1) The basic reaction type of the transformation of alkenes and some reactionsinvolving organic hypervalent iodine (III) reagents and their recent research progresswere summarized. The source, significance and main contents of this topic were alsoillustrated.(2) The reaction of styrene’s C=C bonds transformed to C≡N bonds mediated byPhI(OAc)2was studied. The influence factors of the reaction, such as, the dosage ofPhI(OAc)2and NH4HCO3, solvent, water, temperature and the type of inorganicammonia salt, were investigated. From these experiment results, the optimizedconditions was determined to be PhI(OAc)2(5.5equiv), NH4HCO3(6.0equiv),CH3OH (2mL), H2O (0.5mL),36°C and12h, resulting the benzonitrile in86%yield.(3) Both the terminal and internal alkenes were explored under the the optimized protocol, the most resulting compounds were characterized by1H NMR and13C NMRand partial compounds were determined by GC-MS. The number, property andsubstituted situation of groups connecting with C=C bonds have significant effect onthe transformation C=C bonds to C≡N bonds. The results showed, no matter what theterminal and internal alkenes, aromatic ones are favorable, while aliphatic ones arenot suitable.(4) The reaction mechanism was investigated. By treating alkenes with NH4HCO3in the presence of phenyliodonium diacetate (PIDA) in aqueous medium, the alkeneswere found to proceed via the benzaldehyde as an intermediate.