| Transition metal-catalyzed nitrene transfer reaction represents an important strategy for constructing C-N bonds.Insertion of nitrene to the C=C double bonds can efficiently deliver aziridine compounds,and following attack with nucleophile reagents the ring-opening processes can generate diverse important molecular motifs includeβ-amino alcohol,1,2-diamine,β-halogen ammonia.However,these formally alkene difunctionalization reactions need two-step synthesis and the reaction conditions awaits further improvement with respect to environmental benignity.In this context,the thesis developed a new protocol for the sustainable oxyamination of alkenes in aqueous media via Rh（Ⅱ）-catalyzed nitrene transfer.In the presence of PhI（OAc）2 as the oxidant in combination of sulfamate esterin acidic aqueous conditions,Rh2（esp）2 was capable of catalyzing the aziridination of styrenes,cyclic alkenes and other inactivated C=C double bonds.Followed by in situ ring-opening with water as the nucleophile,diverse amino alcohols were efficiently obtained with 35-96%yields.In comparison to the known oxyamination reactions,our protocol features efficient step-economy,benign conditions,and broad substrate scope.Moreover,the catalytic system could be utilized for the late-stage functionalization of some complex bioactive compounds.The mechanistic studies confirmed the intermediacy of aziridine intermediate,and the acidic aqueous medium serves as Br（?）nsted acid catalyst to activate ring-opening event.products.The dosage of PhI（OAc）2 was found to important parameter affecting the amination chemoselectivity.Preliminary studies showed that the reduction of equivalents would affect the chemoselectivity of the amination process forα-methyl styrenes,leading to the formation of allylic amines in moderate yield.Further investigations are deserved to gain deep insight of this allylic amination transformation. |
