l -Proline catalyzed condensation of salicylaldehydes with ethyl nitroacetate: an efficient access to 3-nitrocoumarins
摘要:
Abstractl-Proline catalyzed condensation of salicylaldehydes and ethyl nitroacetate afforded 3-nitrocoumarins in good to high yields under mild conditions. This organocatalyzed process offers a much improved yield of 3-nitrocoumarins and well tolerates both electron-donating and electron-withdrawing substituents on the phenyl ring. Graphical abstract
An enantioselectiveDiels–Alder reaction of 3-nitrocoumarins has been developed. A tryptophan-derived C 1-symmetric organoammonium thiourea catalyst promoted the reaction of 3-nitrocoumarins with Danishefsky’s diene to give the corresponding adducts with good enantioselectivity (up to 94% ee). One of the resulting adducts was converted into a chiral carbocyclic quaternary β-amino alcohol.
已经开发了 3-硝基香豆素的对映选择性 Diels-Alder 反应。色氨酸衍生的 C 1-对称有机铵硫脲催化剂促进了 3-硝基香豆素与丹麦谢夫斯基二烯的反应,得到具有良好对映选择性(高达 94% ee)的相应加合物。所得加合物之一被转化为手性碳环季 β-氨基醇。
Diastereoselective Tandem Michael Additions of Indoles to 3-Nitrocoumarin Derivatives and Methyl Vinyl Ketone
Tandem Michael additions of indole derivatives to 3-nitrocoumarins 2, followed by MVK, in one pot, has been developed for the synthesis of multi-functionalized 3,4-dihydrocoumarins bearing a quaternary stereocenter. The reaction proceeds with high diastereoselectivities in good to excellent yields.
Intensified synthesis of [3,4-d]triazole-fused chromenes, coumarins, and quinolones
作者:Georg Schwendt、Toma Glasnov
DOI:10.1007/s00706-016-1885-5
日期:2017.1
AbstractEfficient and metal-free synthesis of [3,4-d]triazole-fused chromenes, coumarins, and quinolones has been achieved in an intensified regime using microwave heating. The smooth 1,3-dipolarcycloaddition reaction of heterocyclic nitroalkenes with sodium azide provides a rapid entry into valuable heterocyclic scaffolds with potential biological properties. Graphical abstract
摘要使用微波加热在强化过程中已经实现了[3,4- d ]三唑稠合的色烯,香豆素和喹诺酮的高效无金属合成。杂环硝基烯烃与叠氮化钠的平滑1,3-偶极环加成反应可快速进入有价值的具有潜在生物学特性的杂环支架。 图形概要
Looking for New Targets: Simple Coumarins as Antibacterial Agents
The dramatic worldwide increase of dangerous infections by resistant and multi-resistant microbes makes the
search of new molecules and new chemical entities an important topic in Medicinal Chemistry. As the ideal drug candidate
has not been attained, an intensive search for new and innovative antimicrobials is still needed. A small series of 3-
amino/nitrocoumarins without substitutions or substituted by methyl or methoxy groups at different positions were synthesized
and evaluated for their antibacterial and antifungal activities against clinical isolates of Staphylococcus aureus,
Escherichia coli and Candida albicans strains. Some of these structurally simple molecules exhibited antibacterial activity.
The preliminary SAR study showed that the antibacterial activity against E. coli and S. aureus was dependent on the
kind and position of the substitution pattern at the coumarin moiety.
l-Proline catalyzed condensation of salicylaldehydes with ethyl nitroacetate: an efficient access to 3-nitrocoumarins
作者:Rajesh Kumar Sharma、Priyanka、Diksha Katiyar
DOI:10.1007/s00706-016-1736-4
日期:2016.12
Abstractl-Proline catalyzed condensation of salicylaldehydes and ethyl nitroacetate afforded 3-nitrocoumarins in good to high yields under mild conditions. This organocatalyzed process offers a much improved yield of 3-nitrocoumarins and well tolerates both electron-donating and electron-withdrawing substituents on the phenyl ring. Graphical abstract
Abstractl-Proline catalyzed condensation of salicylaldehydes and ethyl nitroacetate afforded 3-nitrocoumarins in good to high yields under mild conditions. This organocatalyzed process offers a much improved yield of 3-nitrocoumarins and well tolerates both electron-donating and electron-withdrawing substituents on the phenyl ring. Graphical abstract