40473-50-5Relevant articles and documents
Organic Br?nsted acid-catalyzed cycloadditions of o-quinone methides with 1, 3-dicarbonlys: Facile access to xanthenones and chromanones
Kokkuvayil Vasu, Radhakrishnan,Parameswaran, Sasikumar,Puthiyaparambath, Sharathna,Suresh Varma, Sanjay,Thoppe Sivakumar, Priyadarshini
, (2021/06/27)
The in-situ generation of o-quinone methides and their inverse-electron-demand Diels–Alder reaction in the presence of pentacarboxycyclopentadiene—an organic Br?nsted acid—has been reported. The synthesis of xanthenones and chromanones in good to excellen
Catalytic Asymmetric Three-component Hydroacyloxylation/ 1,4-Conjugate Addition of Ynamides
Cao, Weidi,Feng, Xiaoming,Jiang, Mingyi,Li, Xiangqiang,Zhan, Tangyu
supporting information, (2020/06/17)
A highly enantioselective three-component hydroacyloxylation/1,4-conjugate addition of ortho-hydroxybenzyl alcohols, ynamides and carboxylic acids was developed under mild reaction conditions in the presence of a chiral N,N′-dioxide/Sc(OTf)3 complex, which went through in situ generated ortho-quinone methides with α-acyloxyenamides, delivering a range of corresponding chiral α-acyloxyenamides derivatives containing gem(1,1)-diaryl skeletons in moderate to good yields with excellent ee values. The scale-up experiment and further derivation showed the practicality of this catalytic system. In addition, a possible catalytic cycle and transition state model was proposed to elucidate the origin of the stereoselectivity based on X-ray crystal structure of the α-acyloxyenamide intermediate and product.
Regio- A nd Enantioselective Friedel-Crafts Benzhydrylation of Indoles in Carbocyclic Ring with ortho-Quinomethanes: Access to Chiral Diarylindolylmethanes
Chu, Ming-Ming,Chen, Xue-Yang,Wang, Yi-Feng,Qi, Suo-Suo,Jiang, Zhen-Hui,Xu, Dan-Qian,Xu, Zhen-Yuan
, p. 9491 - 9502 (2020/09/03)
The functionalization of indoles in the carbocyclic ring has been achieved via organocatalytic enantioselective Friedel-Crafts benzhydrylation of hydroxyindoles with in situ generated ortho-quinomethanes in oil-water biphases, allowing an efficient access to varied diarylindolylmethanes with a wide substrate scope. The high yields, excellent stereoselectivities, mild conditions, low catalyst loading, and easy scalability also demonstrated the interest of this novel methodology.