Robust, Enantioselective Construction of Challenging, Biologically Relevant Tertiary Ether Stereocenters
作者:Yong Guan、Tadas A. Buivydas、Remy F. Lalisse、Jonathan W. Attard、Rameez Ali、Charlotte Stern、Christopher M. Hadad、Anita E. Mattson
DOI:10.1021/acscatal.1c01095
日期:2021.5.21
A robust, catalytic enantioselective method to construct challenging, biologically relevant, tertiary ether stereocenters has been developed. The process capitalizes on readily accessible bis(oxazoline) ligands to control the facial selectivity of the addition of copper acetylides to benzopyrylium triflates, reactive species generated in situ. Up to 99%, enantiomeric excesses are achieved with a broad
FeCl<sub>3</sub>and ether mediated direct intramolecular acylation of esters and their application in efficient preparation of xanthone and chromone derivatives
作者:Neng Jiang、Su-Yi Li、Sai-Sai Xie、Hequan Yao、Hongbin Sun、Xiao-Bing Wang、Ling-Yi Kong
DOI:10.1039/c4ra10174j
日期:——
The direct intramolecular acylation of esters was developed by using the combined system of FeCl3 with Cl2CHOCH3. This unique cooperative system offered a new and efficient approach to biologically important xanthone and chromone derivatives with regioselectivity. Examples were reported, and control experiments were carried out to examine the effect of the benzyl esters and Cl2CHOCH3.
Enantioselective Dearomative Alkynylation of Chromanones: Opportunities and Obstacles
作者:Anita E. Mattson、Yong Guan、Tadas Buivydas、Remy F. Lalisse、Rameez Ali、Christopher M. Hadad
DOI:10.1055/a-1811-8075
日期:2022.10
A catalytic and highly enantioselective dearomative alkynylation of chromanones has been discovered that enables the construction of biologically relevant tertiary ether stereogenic centers. This methodology is robust, accommodating a variety of alkynes and chromanones. More than 40 substrates tested gave rise to >90% ee. Computational studies have indicated that the optimal indanyl ligand identified
The acaricidal effects of tonka bean, Dipterix odorata, extracts were investigated on Dermatophagoides pteronyssinus, the European house dust mite, and compared with benzyl benzoate as a standard acaricidal compound. A cyclohexane extract was the most effective, with an EC50 = 0.075 g/m(2) after a 24 h period, as compared with benzyl benzoate (0.025 g/m(2)). Bioassay-guided fractionation of this extract led to the isolation of coumarin (1). Pharmacomodulation of this compound led us to test 20 analogues (2-21), which were either synthesized or purchased.
Ru(II)-Catalyzed Selective C–H Amination of Xanthones and Chromones with Sulfonyl Azides: Synthesis and Anticancer Evaluation
作者:Youngmi Shin、Sangil Han、Umasankar De、Jihye Park、Satyasheel Sharma、Neeraj Kumar Mishra、Eui-Kyung Lee、Youngil Lee、Hyung Sik Kim、In Su Kim
DOI:10.1021/jo501709f
日期:2014.10.3
ruthenium-catalyzed selective amination of xanthones and chromones C–H bonds with sulfonyl azides is described. The reactions proceed efficiently with a broad range of substrates with excellent functional group compatibility. This protocol provides direct access to 1-aminoxanthones, 5-aminochromones, and 5-aminoflavonoid derivatives known to exhibit potent anticancer activity.