R. Duddu et al., PREPARATION AND REACTIVITY OF CHIRAL BETA-AMIDO-ALKYLZINC IODIDES ANDRELATED CONFIGURATIONALLY STABLE ZINC ORGANOMETALLICS, Tetrahedron, 50(8), 1994, pp. 2415-2432
Several zinc organometallics bearing at the beta-position a carbamate
or an amido function with an acidic N-H group were prepared using the
direct insertion of zinc dust into the corresponding alkyl iodides in
THF or THF:DMSO mixtures. Most of the starting iodides were obtained f
rom natural alpha-amino acids and the resulting zinc species afforded
after transmetalation with CuCN.2LiCl and reaction with a selection of
relatively reactive electrophiles a variety of polyfunctional 1,2-ami
no alcohol derivatives and carbamates in optically pure form. Several
secondary beta-amido alkyl iodides were converted to the corresponding
chiral zinc reagents and trapped with electrophiles. The configuratio
nal stability of chiral secondary organozinc compounds and the stereoc
hemical course of their reactions were examined.