Copper-catalyzed electrophilic amination of organozinc nucleophiles: documentation of O-benzoyl hydroxylamines as broadly useful R2N(+) and RHN(+) synthons.
[reaction: see text] This paper details new copper-catalyzed electrophilic amination reactions of diorganozinc reagents using O-benzoyl hydroxylamines as electrophilic nitrogen sources that may be accessed in one step. Simple and functionalized aryl, heteroaryl-, benzyl, n-alkyl, sec-alkyl, and tert-alkyl nucleophiles couple with R2NOC(O)Ph and RHNOC(O)Ph reagents in the presence of catalytic quantities of copper salts to provide tertiary and secondary amines, respectively, in generally good yields. In many cases, the product may be isolated analytically pure after a simple extractive workup. The amination process is shown to tolerate a significant degree of steric demand. The amination of nominally unreactive C(aryl)-H bonds via a sequential directed ortho metalation/transmetalation/catalytic amination reaction sequence is detailed. The direct Cu-catalyzed amination of Grignard reagents using cocatalysis by ZnCl2 is described.
Berman
Ashley M
AM
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Johnson
Jeffrey S
JS
D000586:Amination; D000588:Amines / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006898:Hydroxylamines / Q000138:chemical synthesis / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D017967:Zinc Compounds / Q000138:chemical synthesis / Q000737:chemistry*
D000588:Amines; D006898:Hydroxylamines; D017967:Zinc Compounds; C010046:O-benzoylhydroxylamine; D003300:Copper; D008094:Lithium; D009584:Nitrogen