Consecutive catalytic electrophilic fluorination/amination of β-keto esters:: toward α-fluoro-α-amino acids?

Monofluorination of beta-keto esters with Selectfluor (R) (1-chlorometliyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis(tetrafluoroborate)) using CpTiCl3 as a catalyst, followed by amination with diazodicarboxylates using a Cu/Ph-Box catalyst leads to alpha-fluoro-alpha-hydrazino-beta-keto esters in good yields and good selectivities (ee up to 94%). (c) 2006 Elsevier Ltd. All rights reserved.