N-[1-(Benzotriazol-1-yl)alkyl]amides, versatile amidoalkylation reagents. 5. A general and convenient route to N-(.alpha.-alkoxyalkyl)amides
作者:Alan R. Katritzky、Wei Qiang Fan、Michael Black、Juliusz Pernak
DOI:10.1021/jo00028a028
日期:1992.1
N-[1-(Benzotriazol-1-yl)alkyl]amides 2, easily prepared from benzotriazole 1, an aldehyde, and an amide, react readily with a variety of primary and secondary alcohols under mild conditions to give N-(alpha-alkoxyalkyl)amides 3 in good yield.
Novel Use of <i>N</i>-Benzoyl-<i>N,O</i>-acetals as <i>N</i>-Acylimine Equivalents in Asymmetric Heterocycloaddition: An Extended Enantioselective Pathway to β-Benzamido Aldehydes
For the first time, easily available N-(alpha-methoxyalkyl)amides were successfully used as synthetic equivalents of N-acylimines in an asymmetric heterocycloaddition process. The facial-controlled formation of 6-alkoxydihydrooxazines was thus achieved by SnCl4-promoted heterocycloaddition of (R)-O-vinyl pantolactone. By simple acidic hydrolysis of the crude heteroadducts, new beta-aryl- and beta-alkyl-substituted benzamido aldehydes were thus obtained in good overall yields with high enantioselectivities.
Catalyst-free Mannich-type reaction of 1-(N-acylamino)alkyltriphenylphosphonium salts with silyl enolates
reaction of 1-(N-acylamino)alkyltriphenylphosphonium tetrafluoroborates with silyl enolates was developed to prepare β-amino carbonyl compounds. The reported method is a useful approach for the preparation of N-protected β-amino esters as well as N-protected β-amino ketones. The starting 1-(N-acylamino)alkyltriphenylphosphonium tetrafluoroborates are readily available from N-protected α-amino acids. Therefore