72299-18-4Relevant academic research and scientific papers
Transition metal nanoparticles stabilized by ammonium salts of hyperbranched polystyrene: effect of metals on catalysis of the biphasic hydrogenation of alkenes and arenes
Gao, Lei,Kojima, Keisuke,Nagashima, Hideo
, p. 6414 - 6423 (2015)
Abstract Hyperbranched polystyrene bearing ammonium salts (HPS-NR3+Cl-) behaves as an excellent stabilizer of ruthenium, rhodium, iridium, palladium, and platinum nanoparticles from 1 to 3 nm in size uniformly dispersed in the polymer matrix. The catalytic performance of the resulting metal-polymer composites, M@HPS-NR3+Cl-, is dependent on the metal. This dependence was investigated by assessing the hydrogenation of alkenes and arenes. The utility of M@HPS-NR3+Cl- as reusable catalysts in aqueous/organic biphasic systems was demonstrated by examining the catalysis of the hydrogenation of aromatic compounds containing various functional groups by Ru@HPS-NR3+Cl-.
Catalyst-Free Decarboxylation of Carboxylic Acids and Deoxygenation of Alcohols by Electro-Induced Radical Formation
Chen, Xiaoping,Luo, Xiaosheng,Peng, Xiao,Guo, Jiaojiao,Zai, Jiantao,Wang, Ping
supporting information, p. 3226 - 3230 (2020/02/27)
Electro-induced reduction of redox active esters and N-phthalimidoyl oxalates derived from naturally abundant carboxylic acids and alcohols provides a sustainable and inexpensive approach to radical formation via undivided electrochemical cells. The resulting radicals are trapped by an electron-poor olefin or hydrogen atom source to furnish the Giese reaction or reductive decarboxylation products, respectively. A broad range of carboxylic acid (1°, 2°, and 3°) and alcohol (2° and 3°) derivatives are applicable in this catalyst-free reaction, which tolerated a diverse range of functional groups. This method features simple operation, is a sustainable platform, and has broad application.
Sustainable Alkylation of Unactivated Esters and Amides with Alcohols Enabled by Manganese Catalysis
Jang, Yoon Kyung,Krückel, Tobias,Rueping, Magnus,El-Sepelgy, Osama
supporting information, p. 7779 - 7783 (2018/12/14)
The first example of manganese-catalyzed C-alkylation of the carboxylic acid derivatives is reported. The bench-stable homogeneous manganese complex enables the transformation of the renewable alcohol and carboxylic acid derivative feedstock to higher value esters and amides. The reaction operates via hydrogen autotransfer and ideally produces water as the only side product. Importantly, aliphatic-, benzylic-, and heterocyclic-containing alcohols can be used as alkylating reagents, eliminating the need for mutagenic alkyl halides.
General and Mild Cobalt-Catalyzed C-Alkylation of Unactivated Amides and Esters with Alcohols
Deibl, Nicklas,Kempe, Rhett
supporting information, p. 10786 - 10789 (2016/09/09)
The borrowing hydrogen or hydrogen autotransfer methodology is an elegant and sustainable or green concept to construct carbon-carbon bonds. In this concept, alcohols, which can be obtained from barely used and indigestible biomass, such as lignocellulose, are employed as alkylating reagents. An especially challenging alkylation is that of unactivated esters and amides. Only noble metal catalysts based on iridium and ruthenium have been used to accomplish these reactions. Herein, we report on the first base metal-catalyzed α-alkylation of unactivated amides and esters by alcohols. Cobalt complexes stabilized with pincer ligands, recently developed in our laboratory, catalyze these reactions very efficiently. The precatalysts can be synthesized easily from commercially available starting materials on a multigram scale and are self-activating under the basic reaction conditions. This Co catalyst class is also able to mediate alkylation reactions of both esters and amides. In addition, we apply the methodology to synthesize ketones and to convert alcohols into aldehydes elongated by two carbon atoms.
A highly efficient catalytic α-alkylation of unactivated amides using primary alcohols
Yao, Wubing,Ma, Xiaochen,Guo, Le,Jia, Xiangqing,Hu, Aiguo,Huang, Zheng
supporting information, p. 2919 - 2921 (2016/06/13)
The α-alkylation of unactivated amides with alcohols is described. Using a NCP-type pincer Ir complex as the precatalyst and KOtBu as the base, the reactions of secondary or tertiary acetamides with benzyl or nonbenzyl primary alcohols occur at 80 °C, furnishing the alkylation products in good yields. This method represents a practical and green means of α-alkylation of amides in a relatively mild, efficient, and selective manner with low catalyst loadings (0.5 mol %).
Ruthenium hydride/nitrogen tridentate ligand-catalyzed α-alkylation of acetamides with primary alcohols
Kuwahara, Takashi,Fukuyama, Takahide,Ryu, Ilhyong
, p. 13702 - 13704 (2013/08/23)
The α-alkylation reaction of acetamides with primary alcohols to afford the corresponding amides was accomplished effectively using RuHCl(CO)(PPh3)3 as a catalyst, nitrogen tridentate ligand L1 as an additive, and KOtBu as a base. While the addition of bpy was effective only for benzylic alcohols, L1 affected the alkylation reaction when both benzylic and non-benzylic type alcohols were used.
Iridium-catalyzed selective α-alkylation of unactivated amides with primary alcohols
Guo, Le,Liu, Yinghua,Yao, Wubing,Leng, Xuebing,Huang, Zheng
supporting information, p. 1144 - 1147 (2013/04/10)
The first α-alkylation of unactivated amides with primary alcohols is described. An effective and robust iridium pincer complex has been developed for selective α-alkylation of tertiary and secondary acetamides involving a borrowing hydrogen methodology. The method is compatible with alcohols bearing various functional groups. This presents a convenient and environmentally benign protocol for α-alkylation of amides.
Cyclic imidate salts in acyclic stereochemistry: Diastereoselective syn-epoxidation of 2-alkyl-4-enamides to epoxyamides
Maligres,Weissman,Upadhyay,Cianciosi,Reamer,Purick,Sager,Rossen,Eng,Askin,Volante,Reider
, p. 3327 - 3338 (2007/10/03)
Reaction of 2-alkyl-4-enamides with I+ and aqueous sodium bicarbonate results in the diastereoselective formation of the corresponding iodohydrins with essentially no iodolactone by-product. The reaction appears to proceed through a cyclic imidate type intermediate. This methodology has been successfully employed for the synthesis of the epoxide intermediate of the orally active HIV-1 protease inhibitor MK-639 (indinavir sulfate).
