- Cobalt-catalyzed direct α-hydroxymethylation of amides with methanol as a C1 source
-
Herein, we report a cobalt-catalyzed α-hydroxymethylation of amides with methanol under mild conditions. Using CoCl2·6H2O as an inexpensive and efficient catalyst, some important bioactive β-hydroxyamides were obtained in moderate to excellent yields. The
- Ma, Ben,Sun, Rongxia,Yang, Jingya
-
supporting information
p. 1382 - 1385
(2022/02/05)
-
- Iridium-PPh3 Catalysts for Conversion of Amides to Enamines
-
Studies on the deactivation mechanism of the reaction of N,N-dialkylamides with TMDS catalyzed by Vaska's complex, IrCl(CO)(PPh3)2 (1a), triggered the discovery of highly active Ir-PPh3 catalysts: Photochemically activated
- Une, Yuta,Tahara, Atsushi,Miyamoto, Yasumitsu,Sunada, Yusuke,Nagashima, Hideo
-
supporting information
p. 852 - 862
(2019/03/04)
-
- Formamide catalyzed activation of carboxylic acids-versatile and cost-efficient amidation and esterification
-
A novel, broadly applicable method for amide C-N and ester C-O bond formation is presented based on formylpyrrolidine (FPyr) as a Lewis base catalyst. Herein, trichlorotriazine (TCT), which is the most cost-efficient reagent for OH-group activation, was employed in amounts of ≤40 mol% with respect to the starting material (100 mol%). The new approach is distinguished by excellent cost-efficiency, waste-balance (E-factor down to 3) and scalability (up to >80 g). Moreover, high levels of functional group compatibility, which includes acid-labile acetals and silyl ethers, are demonstrated and even peptide C-N bonds can be formed. In comparison to reported amidation procedures using TCT, yields are considerably improved (for instance from 26 to 91%) and esterification is facilitated for the first time in synthetically useful yields. These significant enhancements are rationalized by activation by means of acid chlorides instead of less electrophilic acid anhydride intermediates.
- Huy, Peter H.,Mbouhom, Christelle
-
p. 7399 - 7406
(2019/08/20)
-
- Charge-Transfer Complex Promoted C-N Bond Activation for Ni-Catalyzed Carbonylation
-
A new strategy was developed for activation of C-N bond via formation of an amine-I2 charge-transfer complex, which facilitates the inert C-N bond activation via oxidative addition with Ni(0). This strategy has been successfully applied in the Ni-catalyzed carbonylation of benzylamines via direct insertion of CO into the C-N bond, which provided a straightforward and rapid approach to arylacetamides in the presence of catalytic amounts of I2 and Ni catalyst. Mechanistic studies suggested that a benzyl radical generated via the oxidative addition was involved in the present reaction.
- Yu, Hui,Gao, Bao,Hu, Bin,Huang, Hanmin
-
supporting information
p. 3520 - 3523
(2017/07/17)
-
- Synthesis of Unsymmetrical Diaryl Acetamides, Benzofurans, Benzophenones, and Xanthenes by Transition-Metal-Free Oxidative Cross-Coupling of sp3 and sp2 C-H Bonds
-
A chemo- and regioselective intermolecular sp3 C-H and sp2 C-H coupling reaction for C-C bond formation is described to access unsymmetrical diaryl acetamides under TM-free conditions from sec- and tert-arylacetamides and nitroarenes using tert-butoxide base in DMSO at room temperature. The coupling partners with sensitive functionalities such as chloro, bromo, hydroxy, and cyano were also amenable to the developed reaction. Synthesized α-(2/4-nitroaryl) phenylacetamides have been transformed into biologically important benzofurans, xanthenes, diaryl indoles, and unsymmetrical benzophenones by novel routes without applying a transition metal. Overall, an economical, yet efficient, strategy has been devised to access unsymmetrical diarylacetamides with the possibility of their further elaboration into a variety of biologically important heterocycles. Mechanistic understanding suggests that the reaction proceeds by a nucleophilic addition of a phenylacetamide carbanion, which is generated in the presence of tert-butoxide base, to the para or ortho (if para is substituted) position of nitrobenzene. The formed α-(4-nitrocyclohexa-2,4-dien-1-yl) phenylacetamide anion intermediate oxidized by a basic solution of DMSO or atmospheric oxygen led to the desired sp3 C-H and sp2 C-H coupled α-(2/4-nitroaryl) phenylacetamides.
- Rathore, Vandana,Sattar, Moh.,Kumar, Raushan,Kumar, Sangit
-
p. 9206 - 9218
(2016/10/14)
-
- Catalyst-free amidation of aldehyde with amine under mild conditions
-
A highly efficient, catalyst-free and one-pot procedure for the direct synthesis of amides from aldehydes and amines under mild conditions has been developed. Both aliphatic and aromatic aldehydes with primary or secondary amines are successfully converted to the corresponding amides, and it is observed that reactions can proceed in either aqueous or organic media.
- Yang, Hongyin,Hu, Wenjian,Deng, Shengjue,Wu, Tiantian,Cen, Haiman,Chen, Yiping,Zhang, Dela,Wang, Bo
-
supporting information
p. 5912 - 5915
(2015/08/11)
-
- Carbene radicals in cobalt(II)-porphyrin-catalysed carbene carbonylation reactions; A catalytic approach to ketenes
-
One-pot radicals: Cobalt(III)-carbene radicals, generated by metallo-radical activation of diazo compounds and N-tosylhydrazone sodium salts with cobalt(II) complexes of porphyrins, readily undergo radical addition to carbon monoxide, allowing the catalytic production of ketenes. These ketenes subsequently react with various amines, alcohols and imines in one-pot tandem transformations to produce differently substituted amides, esters and β-lactams in good isolated yields. Copyright
- Paul, Nanda D.,Chirila, Andrei,Lu, Hongjian,Zhang, X. Peter,Debruin, Bas
-
supporting information
p. 12953 - 12958
(2013/10/01)
-
- Cesium carbonate promoted aerobic oxidation of arylacetamides: an efficient access to N-substituted α-keto amides
-
A novel cesium carbonate promoted aerobic oxidation reaction to prepare N-substituted α-keto amides in the presence of catalytic amount of tetra-n-butylammonium bromide was described. This reaction provides a very simple and convenient route from easily a
- Song, Bingrui,Wang, Siyuan,Sun, Caiyun,Deng, Hongmei,Xu, Bin
-
p. 8982 - 8986
(2008/03/18)
-
- Synthesis of indolones via radical cyclization of N-(2-halogenoalkanoyl)- substituted anilines
-
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).
- Nishio, Takehiko,Iseki, Kyoko,Araki, Norihito,Miyazaki, Takenori
-
-
- Synthesis and characterization of some heterocyclic analogues of N,N′-perarylated phenylene-1,4-diamines and benzidines as a new class of hole transport materials
-
Starting from N,N-diarylsubstituted thioureas 20 and thioacetamides 21 a series of heterocyclic analogous of N,N′-perarylated phenylene-1,4-diamines and benzidines was obtained. These compounds represent, as studied by DSC measurements, a new class of hole transporting materials with high thermal stability and high tendency to form stable amorphous states. Moreover, some of the new compounds are, as measured by cyclic voltammetry, easily reversibly oxidized indicating the formation of persistent radical ions. Such compounds, which are, in general, completely substituted by aryl groups at their heterocyclic moieties, have been successfully used as hole-transport materials in OLEDs.
- Schumann, Joerg,Kanitz, Andreas,Hartmann, Horst
-
p. 1268 - 1276
(2007/10/03)
-