2003 Reactions of organo-metal compounds

Reactions of organo-metal compoundsO 0350 Palladium(0) Catalyzed and Copper(I) Promoted Reactions of the Secondary Zinc

Reagent Derived from L-Threonine. — C-3 epimeric secondary zinc reagents are prepared from either diastereoisomeric iodide (VI) or (VII) by using activated zinc dust. The NMR spectrum of the zinc reagents indicate an intramolecular ester carbonyl-zinc coordination. Palladium-catalyzed cross coupling of these reagents with aryl iodides (VIII) affords the β-methyl substituted amino acids (IX) and (X). Applying the copper--catalyzed reaction of α-amino acid zinc reagents with allylic halides (XII) to iodide (VI), allows the preparation of methyl alkenyl substituted α-amino acids (XIII), which are obtained as inseparable mixtures of diastereomers. — (WILSON, I.; JACKSON*, R. F. W.; J. Chem. Soc., Perkin Trans. 1 2002, 24, 2845-2850; Dep. Chem., Univ. Newcastle, Newcastle upon Tyne NE1 7RU, UK; Eng.) — H. Hoennerscheid

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