Novel N , O -Cu(OAc) 2 complex catalysed diastereo- and enantioselective 1,4-addition of glycine derivatives to alkylidene malonates

Newly developed chiral N,O-Cu(OAc)2 complexes were found to catalyse the diastereo- and enantioselective 1,4-addition of glycine derivatives to alkylidene malonates to afford 3-aryl glutamic acids derivatives in good yields (82–98%) and high stereoselectivities (up to 83% for anti and 90% for syn adducts, respectively). High optical purity anti adducts (up to 99% ee) can be obtained after simple recrystallisation, and their conversion to free 3-aryl glutamic acids was demonstrated by a representative example, chlorpheg, via a one pot process in 72% yield.