SYNTHESIS OF 1,1'-BIS(2-AMINO-2-CARBOXYETHYL)FERROCENE (1,1'-FERROCENYLBIS(ALANINE))

The l,1′-disubstituted ferrocenyl amino acid 1 (l,1′-ferrocenylbis(alanine)) was synthesized by two different routes. Optically acitive 1 was obtained by asymmetric hydrogenation of the bis(didehydroamino acid) derivatives 2 followed by deprotection. The bis(didehydroamino acid) derivatives were prepared by a palladium-catalyzed coupling between l,1′-diiodoferrocene and suitably protected 2-amidoacrylates. Alternatively, racemic 1 was obtained via the bis(nitro ester) 6. The key step in this synthesis was the one-step conversion of the nitro compound 6 into the Boc-protected amino acid derivative 3a. © 1990, American Chemical Society. All rights reserved.