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。
α-Keto Acids as Triggers and Partners for the Synthesis of Quinazolinones, Quinoxalinones, Benzooxazinones, and Benzothiazoles in Water
the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil
A niobium-catalyzed coupling reaction of α-keto acids with <i>ortho</i>-phenylenediamines: synthesis of 3-arylquinoxalin-2(1<i>H</i>)-ones
作者:Camila Ebersol、Nicole Rocha、Filipe Penteado、Márcio S. Silva、Daniela Hartwig、Eder J. Lenardão、Raquel G. Jacob
DOI:10.1039/c9gc02662b
日期:——
valuable 3-arylquinoxalin-2(1H)-ones was developed, by the reaction of α-keto acids with ortho-phenylenediamines in the presence of ammonium niobium oxalate (ANO) as a catalyst. The reactions were conducted in only 10 min under ultrasonic irradiation as an alternative energy source, affording water as the only co-product. A total of twenty-three different 3-arylquinoxalin-2(1H)-ones were selectively obtained
在草酸铌铵(ANO)存在下,通过α-酮酸与邻苯二胺的反应,开发了一种获得有价值的3-芳基喹喔啉-2(1 H)-酮的通用方法。作为替代能源,在超声辐射下仅需10分钟即可进行反应,仅提供水作为副产物。通过该原子有效方案,以良好至优异的产率选择性地获得了总共二十三种不同的3-芳基喹喔啉-2(1 H)-。另外,使用1 H– 15 N HMBC实验来揭示所得产物的区域异构现象。
Visible-light-induced, copper(i)-catalysed C-N coupling between o-phenylenediamine and terminal alkynes: one-pot synthesis of 3-phenyl-2-hydroxy-quinoxalines
and terminal acetylenes was performed using simple copper(I) chloride as a catalyst for the synthesis of quinoxaline derivatives. The current method works well for a wide range of electron rich as well as electron poor group-substituted o-phenylenediamines and phenylacetylenes. The key component in the reaction is the direct photo-excitation of in situ generated copper arylacetylide (λabs = 420–480 nm)
Ambient and aerobic carbon–carbon bond cleavage toward α-ketoester synthesis by transition-metal-free photocatalysis
作者:Qing Yu、Yating Zhang、Jie-Ping Wan
DOI:10.1039/c9gc01357a
日期:——
available enaminones enabling efficient synthesis of α-ketoesters is developed. The reactions showing general tolerance to the reactions of primary and secondaryalcohols proceed well under air via Rose Bengal (RB)-based photocatalysis. Particularly, this mild synthetic method has been discovered to tolerate various polyhydroxylated substrates such as phenolic alcohol, diols and triols with an excellent