Study Of Synthesis Of ?-Aminoketone From N-Sulfonyl-1,2,3-Triazole Via N-Sulfinyl Imine

N-sulfonyl-1,2,3-triazole is now becoming one of the most important precursor of diazo compound,which is utilized to produce carbenoid in modern organic synthesis.?-Diazo imine,generated through the Dimroth tautomerization,could then converte to Rhodium carbene and lead to a lot of transformations,such as insertion,cyclopropanation,yelide formation and so forth.Furthermore,in some metal-free cases,following denitrogenation and H-shift of?-diazo imine,ketene imine could be formed and then undergo interesting and beneficial transformations.Recently,it's discovered that Et₂O·BF₃ could act as both electrophile and fluorine resource to react with N-sulfonyl-1,2,3-triazole delivering?-fluoroenamine stereospecifically,also with the promotion of Et₂O·BF₃,N-sulfonyl-1,2,3-triazole could converted to imidazole in nitrile.For some structurally special N-sulfonyl-1,2,3-triazole,such as N-sulfonyl-5-amino-1,2,3-triazole,an unusual intramolecular oxygen transfer from sulfonyl of?-diazo imine to the carbenoid carbon could occur.For instance,?-carbonyl N-sulfinyl imine could be obtained from N-sulfonyl-5-amino-1,2,3-triazole,and such intermediate is a powerful building block in organic synthesis.However,for common N-sulfonyl-1,2,3-triazole,such intramolecular oxygen transfer reaction was not reported.This thesis is aimed at establish an effective method to achieve intramolecular oxygen transfer for common N-sulfonyl-1,2,3-triazole.On the basis of various experiments and investigations,it was found that when N-sulfonyl-1,2,3-triazole was treated with 5 mol%Rh₂?piv?₄,10 mol%AgF,and 1.0equiv NFSI in refluxed 1,2-DCE for 1 h,?-carbonyl N-sulfinyl imine was obtained.If N-methylindole was added,?-aminoketone was yielded in up to 86%yield.The product could be converted to gem-diaryl ketones and densely substituted pyrrole,indicating the potential of the protocol in organic synthesis.NFSI played vital roles in oxidation of rhodium to produce a high valent rhodium which would yield an electron deficient carbene center,which facilited the intramolecular oxygen transfer giving the key intermediate sulfinyl imine.The following nucleophilic addition of indole and oxidation of sulfinyl by NFSI furnished the final product.