An expeditious route to sterically encumbered nonproteinogenic α-amino acid precursors using allylboronic acids

A diastereoselective allylation of N-tert-butane sulfinyl alpha-iminoesters using allylboronic acids is developed to obtain optically active non-proteinogenic alpha-amino acid precursors in good yields and diastereoselectivities. Gram-scale synthesis, broad tolerance of functional groups, excellent stereodivergence, post-synthetic modifications, and easy removal of the chiral auxiliary are some of the key highlights. The protocol is applicable to various amino acids and short peptides, resulting in the incorporation of these precursors at the N-terminal position.

Automated summary

A diastereoselective allylation of N-tert-butane sulfinyl alpha-iminoesters using allylboronic acids has been developed for obtaining optically active non-proteinogenic alpha-amino acid precursors with high yields and diastereoselectivities. This protocol offers gram-scale synthesis, broad functional group tolerance, excellent stereodivergence, post-synthetic modifications, and easy removal of the chiral auxiliary, making it applicable to various amino acids and short peptides for incorporation of these precursors at the N-terminal position.