Auxiliary-assisted Palladium(?)-catalyzed Direct C(sp~3)-H Nitrooxylation Of Alcohols By

Transition metal-catalyzed C-H activation functionalization is one of the hottest research directions in the field of organic synthesis in recent years.This method can efficiently construct carbon-heteroatom chemical bonds.Nitrate ester compounds have important applications in the fields of medicine and energetic materials,but most of their traditional synthesis methods require a pre-activated substrate structure,and only a small number of work that non-activated C(sp³)-H bond is directly converted into nitrate ester structure are reported.Against this background,this paper studies the use of a metal-catalyzed C-H activation method to directly achieve the non-activated C-H bond nitrooxylation reaction.The main content is divided into the following aspects:Using oxime-masked alcohol molecule as a substrate,a variety of experimental conditions were tried to explore the best reaction conditions to achieve non-activated?and?position of substrate nitrooxylation.Finally,when palladium acetate as the catalyst,silver nitrite as the source of nitrate ester,the selectfluor reagent as the oxidant,and 1,2-dichloroethane as the solvent,the reaction carried out by heating to 90?in the air atmosphere,the substrate can form nitrate ester product at the?-position in a yield of 60%.Subsequently,in this paper,many substrate expansion experiments were successfully completed under the optimal reaction conditions.The conditions in this paper can be well compatible with alkyl alcohols and alcohols with aromatic structures,and have good substrate compatibility and applicability.In this paper,we also tried some substrates with different substituents,which can participate in the reaction well under the conditions explored.Finally,13?-position nitrooxylation products of oxime-masked alcohols were obtained in appropriate yields,and the data were characterized by ¹H NMR,¹³C NMR,and HRMS.Then this thesis tried the derivatization reaction of the reaction product.Finally,in order to explore the reaction mechanism,this paper also designed and carried out the reaction mechanism experiment.Based on the analysis of experimental data and previous research results,it is speculated that the reactions studied in this paper have the participation of free radical process.The radical are initiated under heating conditions and oxidants,then the radical are added to the palladium-ring intermediate.Finally,the reduction-elimination process is performed to obtain the product.