| Abstract
| - Homologation of the nucleophilic glycine equivalent Ni-Gly-PABP [Ni(II) complex of glycine Schiffbase with 2-[N-(α-picolyl)amino]benzophenone (PABP)] 2 via alkyl halide alkylations and Michaeladdition reactions was systematically studied as a general method for preparing symmetricallyα,α-disubstituted α-amino acids (sym-α,α-AA). The dialkylation reactions are conducted underoperationally convenient conditions without recourse to inert atmosphere, dried solvents, and lowtemperatures, thus enjoying key advantages of the experimental simplicity and attractive coststructure. The method has been shown to be particularly successful for the dialkylation of complex2 with activated and nonactivated alkyl halides, including propargyl derivatives, affording ageneralized and practical access to the corresponding sym-α,α-AA. This study has also shown somelimitation of the method, as it cannot be extended to α- or β-branched alkyl halides or Michaelacceptors to be used for the dialkylation of glycine equivalent 2. High chemical yields of thedialkylated products, combined with the simplicity of the experimental procedure, render thismethod worth immediate use for multigram scale preparation of the sym-α,α-AA.
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