329729-34-2Relevant academic research and scientific papers
Stereoisomerism in 3-[N-(2-acetoxypropanoyl)-N-acylamino]-quinazolin-4(3H)-ones, enantioselective acylating agents
Al-Schemi, Abdullah G.,Atkinson, Robert S.,Fawcett, John,Russell, David R.
, p. 4413 - 4421 (2000)
The title compounds diacylaminoquinazolinones (DAQs) are enantioselective acylation agents for amines and a detailed study of their stereostructures was undertaken with the aim of understanding how this enantioselectivity arises. The N-N bond in these DAQs is a chiral axis. Even where both N-acyl groups are (S)-2-acetoxypropanoyl, the N-N bond is still a chiral axis because in the most stable conformation of the planar imide moiety, one exolendo orientation of the carbonyl groups is much preferred over the alternative (endolexo) as revealed by NMR spectroscopy. A conformational preference within the 2-acetoxypropanoyl grouping accounts for the presence of a single exolendo conformation in solution for some of these DAQs (see above) but an interconverting exolendo? endolexo mixture for others. Where a single exolendo conformation is present in solution, evidence is presented that this closely resembles the X-ray determined crystal structure. A mechanism for the second acylation step to form these DAQs is proposed, which involves preliminary O-acylation of the 3-(monoacylamino)quinazolinone. The Royal Society of Chemistry 2000.
3-Aminoquinazolinones as chiral ligands in catalytic enantioselective diethylzinc and phenylacetylene addition to aldehydes
Karabuga, Semistan,Karakaya, Idris,Ulukanli, Sabri
, p. 851 - 855 (2014/06/23)
A series of readily known enantiomerically pure 3-aminoquinazolinones 1a-d were synthesised from easily accessible chiral pool α-hydroxy acids and α-amino acids in only four steps without any requirement of chromatography. These quinazolinones were examined as chiral ligands for catalytic enantioselective diethylzinc and phenylacetylene additions to aldehydes. For enantioselective alkylations, the effects of temperature, solvent, diethylzinc and ligand criteria were analysed, and the desired chiral alcohols were obtained in up to 86% ee. 3-Aminoquinazolinones 1a-d were also shown to be very useful ligands in enantioselective alkynylations of aldehydes. Based upon the optimised conditions, the corresponding propargylic alcohols were obtained in up to 94% ee.
