20619-23-2Relevant articles and documents
Solid Superbase-Catalyzed Stereoselective 1,4-Addition Reactions of Simple Amides in Batch and Continuous-Flow Systems
Borah, Parijat,Yamashita, Yasuhiro,Kobayashi, Shū
, p. 3807 - 3812 (2019)
The utilization of a catalytic solid superbase in fine synthesis is challenging. Here, we employed K/γ-Al2O3 catalytically as a highly efficient solid superbase to perform direct 1,4-addition reactions of simple amides with α,β-unsaturated carbonyls. The desired 1,5-dicarbonyl compounds were obtained in high yields with excellent anti-diastereoselectivities. K/γ-Al2O3 showed a Hammett basicity of 37>H_≥35. The solid base was characterized by using TGA-DTA, 27Al solid-state NMR spectroscopy, and XPS to determine the origin of the superbasicity. Continuous-flow synthesis of a 1,5-dicarbonyl compound was demonstrated by using the novel solid superbase-catalyzed 1,4-addition methodology. We have also uncovered the potential of K/γ-Al2O3 in asymmetric 1,4-addition reactions. (Figure presented.).
Visible light photoredox-catalysed intermolecular radical addition of α-halo amides to olefins
Nakajima, Masaki,Lefebvre, Quentin,Rueping, Magnus
supporting information, p. 3619 - 3622 (2014/04/03)
We present α-chloro amides as a new class of α-acetyl radical precursors, which undergo a tin-free, photoredox-catalysed intermolecular α-alkylation with various olefins exclusively in an anti-Markovnikov fashion. The reaction represents a reductive atom
Synthesis of indolones via radical cyclization of N-(2-halogenoalkanoyl)- substituted anilines
Nishio, Takehiko,Iseki, Kyoko,Araki, Norihito,Miyazaki, Takenori
, p. 35 - 41 (2007/10/03)
The radical reactions of N-(2-halogenoalkanoyl)-substituted anilines (anilides) of type 1 have been investigated under various conditions. Treatment of compounds 1a-1o with Bu3SnH in the presence of (2,2′-azobis(isobutyronitrile) (AIBN) afforded a mixture of the indolones (oxindoles) 2a-2o and the reduction products 5a-5o (Table 1). In contrast, the N-unsubstituted anilides 1p-1s, 1u, and 1v gave the corresponding reduction products exclusively (Table 1). Similar results were obtained by treatment of 1 with Ni powder (Table 2) or wth Et3B (Table 3). Anilides with longer N-(phenylalkyl) chains such as 6 and 7 were inert towards radical cyclization, with the exception of N-benzyl-2-bromo-N,2-dimethylpropanamide (6b), which, upon treatment with Ni powder in i-PrOH, afforded the cyclized product 9b in low yield (Table 4). Upon irradiation, the extended anilides 6, 7, 10, and 11 yielded the corresponding dehydrobromination products exclusively (Table 5).