The invention is concerned with novel vinylogous acid derivatives of formula I:
wherein A and R
1
to R
5
are as defined in the description and in the claims, as well as physiologically acceptable salts thereof. These compounds are useful as chymase inhibitors.
carbon-containing cyclobutane-1,3-diones using chiral phosphoric acid catalysis and commercially available oxidants was reported. According to the structure of the substrates, two optimized reaction conditions were developed to afford the corresponding chiral tetronic acid products in ≤93% and ≤95% ee values. This reaction offers the first catalytic asymmetric approach to chiral 5,5-disubstituted tetronic acid derivatives
首次报道了使用手性磷酸催化和市售氧化剂对含季碳环丁烷-1,3-二酮进行高度对映选择性拜耳-维利格氧化。根据底物的结构,开发了两种优化的反应条件,得到了相应的手性季酮酸产物,其ee值≤93%和≤95%。该反应为手性 5,5-二取代特窗酸衍生物提供了第一个催化不对称方法。(−)-vertinolide 的正式不对称合成和 plakinidone B 的首次催化不对称全合成证明了该方法的合成潜力。
Construction of Chiral Cyclobutanone-Fused 4-Aminoquinolines via Sequential Chiral Phosphoric Acid and Palladium Catalysis
one-pot catalytic asymmetric route to novel chiral quaternary-carbon-containing cyclobutanone-fused 4-aminoquinoline derivatives in good to highyields and enantioselectivities is described. This process consists of a chiral phosphoric acid-catalyzed desymmetric carbonyl-amine condensation of prochiral cyclobutane-1,3-diones with 2-halogenated anilines and a Pd-catalyzed coupling reaction of the chiral enaminone
Efficient Synthesis of 3-Aminocyclobut-2-en-1-ones: Squaramide Surrogates as Potent VLA-4 Antagonists
作者:Stephen Brand、Benjamin C. de Candole、Julien A. Brown
DOI:10.1021/ol034701n
日期:2003.6.1
[GRAPHICS]A novel series of uniquely functionalized 3-aminocyclobut-2-en-1-ones has been prepared by facile condensation of a variety of cyclobuta-1,3-diones with a phenylalanine-derived primary amine. These systems subsequently lend themselves to substitution at C-2 by reaction with a variety of electrophilic reagents including N-halosuccinimides, sulfenyl chlorides, and Eschenmoser's salt. Compounds from this novel series are potent antagonists of VLA-4.
VINYLOGOUS ACIDS DERIVATIVES AS CHYMASE INHIBITORS