Metal-free N-H Bond And N-F Bond Insert With α-diazo Carbonyl Compounds

Diazo carbonyl compounds are versatile precursors to access carbene/carbenoid intermediates through the releasing of dinitrogen under suitable conditions. The carbon atom bearing diazonium functional group is mild nucleophilic, which can be intercepted by electrophiles, such as proton acids, positive halogen atoms, activated carbonyl compounds, etc. Sequential displacement of the diazonium group by external nucleophiles, would lead to target functionalized carbonyl compounds. Following this concept, in this thesis, we have developed two novel transformations, including the first N-F bond insertion of diazo carbonyl compounds and metal-free hydroimidation of diazo carbonyl compounds.1.N-F bond insertion of α-diazo carbonyl compoundsAn unprecedented metal-free N-F bond insertion reaction of α-diazo carbonyl compounds with N-Fluorobenzenesulfonimide(NFSI) has been achieved. In this transformation, NFSI was employed as both fluorine and nitrogen sources and the corresponding aminofluorination products were obtained in moderate to excellent yields. According to the mechanistic studies, a plausible reaction pathway were proprosed.2. N-H bond insertion of α-diazo carbonyl compoundsA metal-free process on N-H bond insertion of α-diazo carbonyl compounds was developed. Because of the Pka threshold, dibenzensulfonimide was proved to be the optimal amine source, regarding on the reaction yields and reaction time. Under our optimal conditions, the target N-H insertion products were obtained in good to excellent yields. Similarly, we have performed kinetic studies, and a stepwise pathway without the formation of free carbene intermediate was proposed.Above all, N-F and N-H bonds insertion of α-diazo carbonyl compounds have been realized under metal-free conditions. N-Fluorobenzenesulfonimide and Dibenzenesulfonimide were employed as the reaction partners. C-N and C-F bonds can be constructed in a highly atom economic manner.