The first B(C6F5)3‐catalyzed deoxygenative reduction of amides into the corresponding amines with readily accessible and stable ammonia borane (AB) as a reducing agent under mild reaction conditions is reported. This metal‐free protocol provides facile access to a wide range of structurally diverse amine products in good to excellent yields, and various functional groups including those that are reduction‐sensitive
据报道,在温和的反应条件下,用易于获得且稳定的氨硼烷(AB)作为还原剂,将酰胺进行的首次B(C 6 F 5)3催化脱氧还原为相应的胺。该无金属方案可轻松获得各种结构多样的胺产品,且收率高至优异,并且对各种官能团(包括对还原敏感的官能团)均具有良好的耐受性。该新方法也适用于手性酰胺底物,而不会破坏对映体的纯度。BF 3 OEt 2助催化剂在该反应中的作用是通过酰胺-硼加合物的原位形成来活化酰胺羰基。
Ru‐Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
ruthenium(II)‐catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2‐methylallyl)2(COD)], 1,1,1‐tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding
首次报道了使用HCO 2 H / NEt 3作为还原剂的钌(II)催化的酰胺脱氧转移胺成胺。催化剂体系由[Ru(2-甲基烯丙基)2(COD)],1,1,1-三(二苯基膦甲基)乙烷(triphos)和双(三氟甲烷磺酰亚胺)(HNTf 2)在将各种仲酰胺和叔酰胺脱氧还原成相应的胺方面表现出色,选择性极好,并且对包括还原敏感基团在内的官能团表现出很高的耐受性。氢源和酸助催化剂的选择对于催化至关重要。机理研究表明,通过借入氢对原位生成的醇和胺进行还原胺化是主要途径。
Metal-free tandem cyclization/hydrosilylation to construct tetrahydroquinoxalines
B(C6F5)3-Catalyzed tandem cyclization/hydrosilylation for the step-economical construction of 1,2,3,4-tetrahydroquinoxalines from readily available starting materials has been developed.
B(C6F5)3催化的串联环化/氢硅烷化反应,可从易得的起始物构建1,2,3,4-四氢喹啉。
pH-Regulated transfer hydrogenation of quinoxalines with a Cp*Ir–diamine catalyst in aqueous media
The combination of [Cp*IrCl2](2) with N-(2-aminoethyl)-4-(trifluoromethyl)benzenesulfonamide constitutes an efficient catalyst for selective transfer hydrogenation of a variety of quinoxalines in water with HCOONa as the hydrogen source, affording the corresponding tetrahydroquinoxalines in good to excellent yields. The catalyst is air-stable, and the reduction could be performed without nitrogen protection. The aqueous phase reduction is shown to be highly pH-dependent, with acidic pH leading to better results. There exits a pH window for optimum rate, and the use of HOAc/NaOAc buffer solution is essential for maintaining a stable pH during the reaction. (C) 2011 Elsevier Ltd. All rights reserved.
Searching for Novel Inhibitors of the<i>S. aureus</i>NorA Efflux Pump: Synthesis and Biological Evaluation of the 3-Phenyl-1,4-benzothiazine Analogues
作者:Tommaso Felicetti、Rolando Cannalire、Maria Sole Burali、Serena Massari、Giuseppe Manfroni、Maria Letizia Barreca、Oriana Tabarrini、Bryan D. Schindler、Stefano Sabatini、Glenn W. Kaatz、Violetta Cecchetti
DOI:10.1002/cmdc.201700286
日期:2017.8.22
overexpression of effluxpumps such as NorA of Staphylococcus aureus leads to a sub-lethal concentration of the antibacterial agent at the active site that in turn may predispose the organism to the development of high-level target-based resistance. With an aim to improve both the chemical stability and potency of our previously reported 3-phenyl-1,4-benzothiazine NorA inhibitors, we replaced the benzothiazine