Selective reactions on a functional group of polyhydroxy compounds are extremelyuseful in organic synthesis, especially in the field of carbohydrate and nucleosidechemistry. Indirect methods for the selective reaction on a functional group ofpolyhydroxy compounds involve the use of protective groups. In order to utilize thismethodology efficiently, selective protection and deprotection of ceftain hydroxy groupswithin the polyhydroxy compound are required.Ketal formation is most commonly used f… 相似文献
Summary: We developed a facile approach to hyperbranched polymers by applying a superelectrophilic reaction within an A2 + B3 strategy. A significant reactivity difference between the intermediate and the starting material was utilized to avoid gelation in the A2 + B3 polymerization. A number of hyperbranched poly(arylene oxindole)s were achieved in a one‐step polymerization and characterized by NMR spectroscopy and gel permeation chromatography. Moreover, further modifications at the interior and exterior of the resulting polymers were explored as well.
Structure of the hyperbranched polymers produced using the A2 + B3 approach. 相似文献
A facile and convenient protocol was developed for the synthesis of symmetrical and unsymmetrical 3,3-di(indolyl)indolin-2-ones in low reaction times (22–35 min) and high yields (85–95%) using KSF as an efficient recyclable heterogeneous catalyst. 相似文献
We have reported DBU-catalyzed one-pot synthesis of biologically and pharmacologically important spiropyrans from condensation of malononitrile/ethyl cyanoacetate, 1,3-dicarbonyl compounds, and ninhydrin/acenaphthequinone/istain in good yields. This new protocol employing DBU, which is a green, recyclable, and inexpensive catalyst, offers advantages such as mild reaction conditions, short reaction times, and easy isolation of products. The structures have been confirmed by x-ray analysis. [Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] 相似文献
An efficient synthesis of 3,3-di(1H-indol-3-yl)indolin-2-ones and 2,2-di(1H-indol-3-yl)-2H-acenaphthen-1-ones via a reaction of various isatins or acenaphthenequinone with indoles in the presence of p-methylbenzene sulfonic acid (p-TSA) in CH2Cl2 at room temperature is described. The advantages of this method include good reaction yield, simple workup procedure, and mild reaction condition. 相似文献
The first cyclization/decarboxylation reaction of isatins with acyl chlorides promoted by 4‐dimethylaminopyridine (DMAP) was described and a series of desired 3‐alkenyl‐oxindoles were obtained in good yields (up to 80%) and E/Z selectivities (up to 6.4/1). This protocol provided a new and feasible access to 3‐alkenyl‐oxindoles. 相似文献
An easy protocol for the synthesis of enaminone attached 3-substituted-3-hydroxy-2-oxindoles has been demonstrated by reaction of isatin and cyclic enaminone in water. The developed catalyst-free reaction has the advantage of being atom-economical, eco-friendly, and benign reaction conditions. The broader substrate scope, experimentally simple procedures, and easy purification of products with high yield further make this method attractive and useful. 相似文献
A facile and green synthetic route was developed for the preparation of dapagliflozin (1), a selective sodium-dependent glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes. Key reaction steps include a direct Friedel–Crafts acylation and a synthesis of diaryl ketal moiety in one-pot manner without waste water generation. Furthermore, the reduction of the diaryl ketone and C-phenylglucoside were achieved in one-pot manner to generate dapagliflozin (1) more efficiently. The synthetic route featured the usage of commercial available and easily handling reagents with shorter reaction steps and less waste disposal. 相似文献