Syntheses and reactions of optically active α-aminoallenylstannanes and α-aminopropargylboranes
An efficient synthesis of α-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 β-amino acids, azasugars, and deoxyaminohexoses. Imines underwent reaction with this stannane to give 1,2-diamines. The related propargylborane reacts with aldehydes to produce allenyl carbinols. The Co2(CO)6 complexes of propargyloxazolidinones were developed as an α-aminopropargyl cation equivalent.