tested as chiral auxiliaries in the stereoselectivesynthesis of β-lactams by condensation of the titanium enolates of 2-pyridyl thioesters with chiral imines. The amines were selected among the following classes of compounds: benzylic amines, β-aminoalcohols, β-heterosubstituted α-aminoesters. Inexpensive and available in both enantiomeric forms α-methylbenzylamine was identified as the chiral auxiliary
The enolates derived from 2-pyridylthioesters by reaction with BCl3 ·SMe2 and enantiomerically pure aminoalcohols react with aromatic imines in an enantioselective fashion (ee up to 78%) to afford β-lactams in a convenient one-pot procedure.
Stereospecific Preparation of γ-Lactam Derivatives via Ring Expansion of<i>cis</i>and<i>trans</i>β-Lactam Derivatives: α-Substituent Effect of β-Lactam Derivatives
作者:Mi-Ji Lee、Chuljin Ahn
DOI:10.1002/bkcs.10697
日期:2016.4
The various substituted γ‐lactamderivatives have been prepared stereospecifically via ring expansion from the corresponding β‐lactamderivatives. The stereochemistry of γ‐lactams with aryl and alkyl substituents on C‐3 has been investigated systematically. The former, which have phenyl or thiophenyl group on C‐3 has shown a single anti, anti γ‐lactam diastereomer. The latter, which have methyl or
Highly diastereoselective synthesis of β-lactams by addition of titanium enolates of 2-pyridyl thioesters to chiral imines
作者:Rita Annunziata、Mauro Cinquini、Franco Cozzi、Pier Giorgio Cozzi
DOI:10.1016/s0040-4039(00)91874-4
日期:1992.2
Addition of titanium enolates of 2-pyridyl thioesters to chiral imines derived from alkoxy aldehydes occurs with good diastereofacial control, and opens a simple access to important carbapenem antibiotics.
The present invention provides compounds having the general structure A, or a pharmaceutically acceptable derivatives thereof:
wherein R is an alkyl group, and R
1
comprises at least one moiety selected from a group consisting of an alkyl, an alkenyl, an aryl, a heterocycle, hydroxyl, ester, amido, aldehyde, and a halogen.