91639-92-8Relevant articles and documents
A Chemoselective α-Oxytriflation Enables the Direct Asymmetric Arylation of Amides
Li, Jing,Berger, Martin,Zawodny, Wojciech,Simaan, Marwan,Maulide, Nuno
supporting information, p. 1883 - 1891 (2019/07/08)
Until recently, the direct oxidative oxysulfonylation of carbonyl compounds was limited to ketones. Here, we report the first direct oxytriflation of simple, non-activated amides. Amide umpolung with triflic anhydride and pyridine-N-oxide in the absence of external nucleophiles directly leads to the formation of reactive α-triflates in a single step, which provides a platform for the deployment of valuable downstream α-functionalization reactions. The utility of this method was demonstrated by in situ clean conversion to their corresponding bromides, as desirable starting materials for nickel-catalyzed deracemizing enantioselective arylation. This approach not only enables a telescoped asymmetric arylation of unsubstituted amides but also extends its scope because of the broad chemoselectivity and functional group tolerance of the method. Amides bearing a functional group in α-position are found in many natural products and drugs. The direct α-functionalization of amides is one of the most popular approaches to access these moieties. Classically, the α-functionalization of amides has been dominated by enolate chemistry; however, carboxamides are among the least C-H acidic carbonyl derivatives, and the presence of further carbonyl or carboxyl groups (such as esters and ketones) is therefore not usually tolerated. Here, we report the first direct α-oxytriflation of simple, non-activated amides using triflic anhydride and pyridine-N-oxide in the absence of external nucleophiles, which provides a platform for the deployment of valuable downstream α-functionalization reactions. The utility of this method was demonstrated by in situ clean conversion to the corresponding bromides, which are valuable starting materials for nickel-catalyzed deracemizing enantioselective arylation. A direct and chemoselective α-oxytriflation of simple and non-activated amides has been developed. This approach provides a platform for the development of valuable downstream α-functionalization reactions of amides. Furthermore, the combination of α-oxytriflation of amides and nickel-catalyzed Suzuki reaction provides an efficient approach for direct asymmetric α-arylation of simple amides.
Ruthenium-catalyzed C7 amidation of indoline C-H bonds with sulfonyl azides
Pan, Changduo,Abdukader, Ablimit,Han, Jie,Cheng, Yixiang,Zhu, Chengjian
supporting information, p. 3606 - 3609 (2014/04/03)
A ruthenium-catalyzed direct C7 amidation of indoline C-H bonds with sulfonyl azides was developed. This procedure allows the synthesis of a variety of 7-amino-substituted indolines, which are useful in pharmaceutical. The good functional tolerances, as well as the mild conditions, are prominent feature of this method.
One-pot cyclization of 2-aminophenethyl alcohols: A novel and direct approach to the synthesis of N-acyl indolines
Wang, Zengxue,Wan, Wen,Jiang, Haizhen,Hao, Jian
, p. 9364 - 9367 (2008/03/13)
(Chemical Equation Presented) A unique one-pot cyclization of 2-aminophenethyl alcohols with carboxylic acids in the presence of PPh 3, CCL4, and NEt3 furnished the formation of N-acyl indolines in good to excellent yields. This new approach provides an efficient, scalable, low-cost, and direct access to the biologically important indolines which are further oxidizable to indoles and oxindoles.
