Lewis acid-promoted Friedel-Crafts alkylation reactions with alpha-ketophosphate electrophiles.
The BF(3).OEt(2)-promoted nucleophilic substitution of alpha-aryl-alpha-ketophosphates to afford alpha,alpha-diaryl ketone products is described. Electron-rich alpha-ketophosphates perform best, with electron-neutral and electron-poor substrates also tolerated. The reaction is tolerant of a range of aromatic, heteroaromatic, and nonaromatic nucleophiles, with yields ranging from 44% to 84%. Enantioenriched starting material yields racemic product, suggesting an S(N)1 pathway via an acylcarbenium ion.
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Austin G
AG
Smith
Jeffrey S
JS
Johnson
D000143:Acids / Q000737:chemistry*; D000478:Alkylation; D004583:Electrons; D007659:Ketones / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry*; D013237:Stereoisomerism
D000143:Acids; D007659:Ketones; D010710:Phosphates