N,O-Bis(trifluoroacetyl)hydroxylamine as a Useful Electrophilic Nitrogen Source:  Catalytic Synthesis of N-(Trifluoroacetyl)sulfilimines

Abstract

[formula: see text] In the presence of catalytic quantites of Cu(OTf)2 the novel hydroxamic acid anhydride salt functions competently in the trifluoroacetamidation of sulfides to afford N-(trifluoroacetyl)sulfilimines. The salient features of this salt include its ease of synthesis from the inexpensive, commercially available starting materials trifluoroacetic anhydride and hydroxylamine hydrochloride.

Light‐Induced Ruthenium‐Catalyzed Nitrene Transfer Reactions: A Photochemical Approach towards N‐Acyl Sulfimides and Sulfoximines

“…[4] Our interest has been focused on the application of such sulfur reagents in asymmetric catalysis. [6][7][8][9][10][11][12][13] However, only few such methods give direct access to Nacylated derivatives, which are synthetically valuable because of the ease of subsequent N functionalization. [6][7][8][9][10][11][12][13] However, only few such methods give direct access to Nacylated derivatives, which are synthetically valuable because of the ease of subsequent N functionalization.…”

“…[5] For most synthetic approaches towards sulfimides and sulfoximines, sulfur imidations of sulfides and sulfoxides, respectively, are key transformations, and consequently several protocols have been developed. [7] Other methods involve the use of imidation reagents such as N-phenyliodonio carboxamide tosylates, [8] N,O-bis(trifluoroacetyl)hydroxylamine in combination with a catalytic amount of a copper(II) salt, [9] nitridomanganese(V) complexes with trifluoroacetic anhydride, [10] and trifluoroacetamide in the presence of a catalytic amount of a rhodium(II) complex. An early example stems from Swern and co-workers, who prepared Nacyl sulfimides by reaction of sulfides with N-bromoacetamides and subsequent treatment of the resulting N-acetylimino sulfonium bromides with base.…”

“…[5] For most synthetic approaches towards sulfimides and sulfoximines, sulfur imidations of sulfides and sulfoxides, respectively, are key transformations, and consequently several protocols have been developed. [6][7][8][9][10][11][12][13] However, only few such methods give direct access to Nacylated derivatives, which are synthetically valuable because of the ease of subsequent N functionalization. An early example stems from Swern and co-workers, who prepared Nacyl sulfimides by reaction of sulfides with N-bromoacetamides and subsequent treatment of the resulting N-acetylimino sulfonium bromides with base.…”

“…An early example stems from Swern and co-workers, who prepared Nacyl sulfimides by reaction of sulfides with N-bromoacetamides and subsequent treatment of the resulting N-acetylimino sulfonium bromides with base. [7] Other methods involve the use of imidation reagents such as N-phenyliodonio carboxamide tosylates, [8] N,O-bis(trifluoroacetyl)hydroxylamine in combination with a catalytic amount of a copper(II) salt, [9] nitridomanganese(V) complexes with trifluoroacetic anhydride, [10] and trifluoroacetamide in the presence of a catalytic amount of a rhodium(II) complex. [11] Mechanistically, they appear to proceed via Nacyl nitrenes or the corresponding (metal)nitrenoids.…”

“…We assume that the light provides the essential energy for the formation of a reactive rutheno Nacyl nitrene intermediate without reaching the higher level of energy required for the Curtius rearrangement which leads to isocyanates. [16] Other ruthenium porphyrin catalysts such as [Ru(TMP)CO] and [Ru(F 20 TPP)CO], as well as [RuCl 2 (p-Cym)] 2 and [Rh 2 (OAc) 4 ] were less efficient or ineffective ( Table 1, entries [8][9][10][11][12][13]. [15,17] In terms of solvents, toluene proved to be superior over CH 2 Cl 2 , THF, or acetonitrile ( Table 1, entry 3 versus entries [14][15][16]).…”