- Carbonylative coupling of an amino acid-derived organozine reagent with functionalized aryl iodides: Synthesis of kynurenine
-
The utility of the palladium(o) catalysed reaction of the serine-derived organozinc reagent 6 with functionalized aryl iodides, under a carbon monoxide atmosphere, to give protected 4-aryl-4-oxo α-amino acids 8 is illustrated by a short synthesis of L-kynurenine.
- Jackson,Turner,Block
-
-
Read Online
- Carbonylative coupling of organozinc reagents in the presence and absence of aryl iodides: Synthesis of unsymmetrical and symmetrical ketones
-
The utility of the palladium(o) catalysed reaction of the iodoalanine-derived organozinc reagent 6a with functionalised aryl iodides, under a carbon monoxide atmosphere, to give protected 4-aryl-4-oxo α-amino acids 8, is illustrated by a short synthesis of L-kynurenine 4. Treatment of functionalised organozinc reagents with catalytic tetrakis(triphenylphosphine)palladium(0) under an atmosphere of carbon monoxide in the absence of any electrophile leads to the formation of symmetrical functionalised ketones 9 in good yields. This reaction is illustrated by a one-step synthesis of protected (2S,6S)-4-oxo-2,6-diaminopimelic acid 9a from commercially available compounds. It has been established that adventitious molecular oxygen plays a key role in the formation of the symmetrical ketones 9, and that rigorous exclusion of oxygen can result in substantially higher yields of ketones 8 in the cross-coupling with some aromatic iodides.
- Jackson, Richard F. W.,Turner, Debra,Block, Michael H.
-
p. 865 - 870
(2007/10/03)
-