4017-00-9Relevant academic research and scientific papers
Continuous-Flow Amide and Ester Reductions Using Neat Borane Dimethylsulfide Complex
?tv?s, Sándor B.,Kappe, C. Oliver
, p. 1800 - 1807 (2020/02/27)
Reductions of amides and esters are of critical importance in synthetic chemistry, and there are numerous protocols for executing these transformations employing traditional batch conditions. Notably, strategies based on flow chemistry, especially for amide reductions, are much less explored. Herein, a simple process was developed in which neat borane dimethylsulfide complex (BH3?DMS) was used to reduce various esters and amides under continuous-flow conditions. Taking advantage of the solvent-free nature of the commercially available borane reagent, high substrate concentrations were realized, allowing outstanding productivity and a significant reduction in E-factors. In addition, with carefully optimized short residence times, the corresponding alcohols and amines were obtained in high selectivity and high yields. The synthetic utility of the inexpensive and easily implemented flow protocol was further corroborated by multigram-scale syntheses of pharmaceutically relevant products. Owing to its beneficial features, including low solvent and reducing agent consumption, high selectivity, simplicity, and inherent scalability, the present process demonstrates fewer environmental concerns than most typical batch reductions using metal hydrides as reducing agents.
Sunlight-Driven Forging of Amide/Ester Bonds from Three Independent Components: An Approach to Carbamates
Zhao, Yating,Huang, Binbin,Yang, Chao,Chen, Qingqing,Xia, Wujiong
supporting information, p. 5572 - 5575 (2016/11/17)
A photoredox catalytic route to carbamates enabled by visible irradiation (or simply sunlight) has been developed. This process leads to a novel approach to the construction of heterocyclic rings wherein the amide or ester motifs of carbamates were assembled from three isolated components. Large-scale experiments were realized by employing continuous flow techniques, and reuse of photocatalyst demonstrated the green and sustainable aspects of this method.
Selective mono-N-alkylation of 3-amino alcohols via chelation to 9-BBN
Bar-Haim, Galia,Kol, Moshe
, p. 3549 - 3551 (2007/10/03)
(Chemical Equation Presented) A method for selective mono-N-alkylation of amino alcohols is introduced. This method relies on formation of a stable chelate with 9-BBN, which serves in the dual roles of protecting and activating the amine group. Three prot
Unusual reactivity of zinc borohydride - Reduction of amides to amines
Narasimhan,Madhavan,Balakumar,Swarnalakshmi
, p. 391 - 394 (2007/10/03)
Zinc borohydride reduces secondary amides to the corresponding N-ethyl amines in excellent yields. The reduction requires only stoichiometric quantities of hydride and does not require the addition of any Lewis acid. The amides are isolated by simple hydrolysis of the reaction mixture.
Synthesis and structure-activity relationships of N-substituted 2-[(2-imidazolylsulfinyl)methyl]anilines as a new class of gastric H+/K+-ATPase inhibitors
Yamakawa,Matsukura,Nomura,Yoshioka,Masaki,Igata,Okabe
, p. 1746 - 1752 (2007/10/02)
A series of N-substituted 2-[(2-imidazolylsulfinyl)methyl]anilines was synthesized and evaluated for its biological activity against H+/K+-ATPase prepared from rabbit stomach and gastric acid secretions in Heidenhain pouch dogs. Monoalkyl substituents on the nitrogen atom of the aniline moiety markedly inhibited the enzyme activity to the same degree as omeprazole, a representative H+/K+-ATPase inhibitor. Most of these compounds, administered at 3 mg/kg i.v. inhibited histamine-stimulated gastric acid secretion. The inhibitory activity of these derivatives on the enzymes at pH 6.0 was more potent than that at pH 7.4, and was distinctly correlated to stability in aqueous solution at pH 5.0.
