Green Oxidation Of Benzylamines And The Reaction Of Alcohols/Phenols With DCMT-Activated DMSO

Green oxidation of primary benzylamines to imines and a new synthesis of methylene acetals are reported in this dissertation.A new and clean oxidation of primary benzylamines to imines is reported, using H₂O₂ in water at room temperature catalyzed by 0.08 equiv of V2O5, in the first part of this dissertation. The reaction conditions are mild. And the products are collected by simple filtrations or extraction in good to quantitative yields (64-100%). The system gives nitron by oxidation of secondary benzylamines. Furthermore, a benzylic anion-involved mechanism is proposed based on the experiments.A new and efficient synthesis of methylene acetals has is in the second part of this dissertation. The reaction of alcohols with DCMT-activated DMSO gives methylene acetals, compatible with substrates bearing acid-labile founctional groups in toluene. The yields for the products from steroids are the best to our knowledge. The operation is simple, and requires inexpensive and commercially available reagents. In an attempted synthesis of methylene acetal of phenols, we discovered the rather surprising formation of dimerized phenolic aldehydes, which are of new skeletons, not known in the literatures. Plausible mechanism is proposed based on the experiments and proven by deuterium-products.In conclusion, green oxidation of benzylamines and synthesis of methylene acetals reported herein is operationally simple, and requires inexpensive and commercially available reagents, which represent new useful tools in organic and medicinal chemistry. Furthermore, we have found a kind of compounds with new skeletons, and proposed a plausible mechanism, which is useful for the further research.