N-Hydroxyphthalimide: What Else Can You Ask For?

(A) The 'Mitsunobu-like' reaction between a supported NHPI derivative using imidazole as a base followed by treatment with methylamine gives the corresponding primary or secondary O-alkyl hydroxylamines isolated in very high purity and in good yields11 [figure] (B) The silyl-hydroxylation of olefins bearing electron-withdrawing groups is accomplished by the reaction of NHPI with a silane. The trialkylsilyl radical adds to the olefin to form an intermediate that, when trapped by molecular oxygen, forms the corresponding alcohol. The silyl-hydroxylation of olefins takes place with yields ranging from 61-99% and with very good selectivity12 [figure] (C) The difficult oxidation of ethers to the related oxygen-containing compounds is accomplished with N-hydroxyphtalimide under an NO atmosphere. This reaction gives good and selective conversion of benzylic ethers to the corresponding aldehydes 13 [figure] (D) The radical addition of masked aldehydes (1,3-dioxolanes) to electr n-deficient alkenes is achieved using NHPI and benzoyl peroxide as polarity reversal catalyst in yields ranging from 46-88%. The tandem version of the reaction was also carried out using the same mild conditions14 [figure] (E) The metal-free catalytic aerobic oxidation of primary olefins by the in situ generation of peracetic acid from acetaldehyde is carried out by mixing all the reagents in the presence of N-hydroxyphtalimide and under an atmospheric pressure of oxygen. The isolated yield of the epoxides goes up to 96%.7 [figure] (F) The direct nitration of aliphatic C-H bonds is performed under mild conditions by reacting NHPI with alkanes in a NO2 atmosphere at 70 °C and in the presence of air. A variety of alkanes were successfully nitrated by this NO/NHPI system in very useful yields15[figure]. © Georg Thieme Verlag Stuttgart.