444997-80-2Relevant articles and documents
Optically active aromatic and heteroaromatic α-amino acids by a one-pot catalytic enantioselective addition of aromatic and heteroaromatic C-H bonds to α-imino esters
Saaby, Steen,Bayon, Pau,Aburel, Pompiliu S.,Jorgensen, Karl Anker
, p. 4352 - 4361 (2002)
The development of a practical one-pot catalytic enantioselective procedure for the synthesis of non-natural aromatic and heteroaromatic α-amino acids is reported. Starting from readily available starting materials and application of a chiral BINAP-Cu(I) catalyst, the optically active products are formed with readily removable N-protecting groups. The scope of the reaction is demonstrated by the addition of substituted furans, thiophenes, pyrroles, and aromatic compounds to N-alkoxy-carbonyl-α-imino esters in good yields and with enantioselectivities up to 96% ee for the furans, 93% ee for the thiophenes, and 98% for the aromatic compounds. The protecting groups are readily removed, and various transformations of the aromatic and heteroaromatic a-amino acids are demonstrated. The coordination of the N-alkoxycarbonyl α-imino ester to the chiral BINAP-Cu(I) complex and the enantioselectivity of the catalyst is discussed on the basis of the DFT calculations and X-ray crystallographic data.
