Serine derived zinc reagent

Dunn, MJ, Jackson RFW, Stephenson GR (1992) Reactions of a serine-derived zinc/cop-per reagent with tricarbonyl(cyclohexadienyl) iron salts synthesis of protected amino acids. Synlett 905-906. doi 10.1055/sl99221536... 

Functionalized zinc cuprates such as the serine-derived zinc-copper reagent 344 react under mild conditions with ClPPh2 (Scheme 2-116). The resulting phosphine was protected as a sulfide providing the enantiomerically pure thiophosphane 345 in 75%... 

One particular aspect of this chemistry is in the preparation of zinc homoenolates prepared from P-iodoesters (Scheme 2.33). This chemistry becomes particularly significant with p-iodoesters 2.95 derived from the amino acid serine 2.94. These are useful for the synthesis of novel amino acids by Negishi coupling with aryl and acyl halides (Scheme 2.34). Coupling of a complex peptidyl aryl iodide 2.98 with a zinc reagent 2.99 of this type was a late step in a synthesis of a cyclic tripeptide and aminopeptidase inhibitor OF494-III 2.100 (Scheme 2.35). ... 

The preparation of alkylzinc iodides is facilitated if the reaction is performed in THF and NMP mixtures. Such solutions of Me02C(CH2)4ZnI add to benzaldehyde in the presence of TMSCI (2 equiv.) in 70% yield.33 The use of ultrasound also promotes the formation of organozinc compounds.34>34a 34e This procedure proved to be especially useful for the preparation of Jackson reagent 6 derived from serine. In the presence of a copper(l) or palladium(O) catalyst, this zinc derivative reacts with various electrophiles (Scheme 1) 3S,3Sa-3Sj 0f z nc reagent 7 leading to methyl but-3-enoate and the zinc amide... 

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