Syntheses and reactions of optically active alpha-aminoallenyistannanes and alpha-aminopropargylboranes

An efficient synthesis of alpha-aminoallenylstannane from propargyloxazolidinone has been developed. It undergoes reaction with aldehydes to give homopropargylic alcohols with high syn selectivity. Epoxides undergo a similar reaction preceded by rearrangement to the aldehyde. These alcohols were used in the synthesis of beta-amino acids, azasugars, and deoxyammohexoses. Imines underwent reaction with this stannane to give 1,2-diamines. The related propargylborane reacts with aldehydes to produce allenyl carbinols. The Co-2(CO)(6) complexes of propargyloxazolidinones were developed as an alpha-aminopropargyl cation equivalent.