One-Pot Deoxygenation and Substitution of Alcohols Mediated by Sulfuryl Fluoride
作者:Maxim Epifanov、Jia Yi Mo、Rudy Dubois、Hao Yu、Glenn M. Sammis
DOI:10.1021/acs.joc.0c02557
日期:2021.3.5
intermediates. This strategy allows the expansion of SO2F2-mediated one-pot processes to include radical reactions, where the alkyl halides can also be exploited in the one-pot deoxygenation of primary alcohols under mild conditions (52–95% yield). This strategy can also enhance the scope of substitutions to nucleophiles that are previously incompatible with one-pot SO2F2-mediated alcohol activation and enables
硫酰氟是用于一键活化和衍生化脂肪醇的有价值的试剂,但是高反应性的烷基氟硫酸烷基酯中间体限制了可以进行的反应类型以及反应范围。在本文中,我们报道了SO 2 F 2介导的醇取代和脱氧方法,该方法依赖于氟代硫酸盐向烷基卤化物中间体的转化。该策略允许扩展SO 2 F 2介导的一锅法包括自由基反应,其中烷基卤也可在温和条件下(52-95%的收率)用于伯醇的一锅法脱氧。这种策略还可以扩大以前与一锅SO 2 F 2介导的醇活化不相容的亲核试剂的取代范围,并能够以54-95%的产率取代伯醇和仲醇。手性仲醇具有高度立体特异性(90-98%ee)的双亲核取代,且整体保留构型。
Access to Aromatic Ring-Fused Benzimidazoles Using Photochemical Substitutions of the Benzimidazol-2-yl Radical
作者:Fawaz Aldabbagh、Joanne O’Connell、Eoin Moriarty
DOI:10.1055/s-0032-1316775
日期:——
onto the benzimidazole-2-position. Photochemical five-, six-, and seven-membered cyclizations from 2-iodo-1-(ω-arylalkyl)-1H-benzimidazoles are described. This method of producing aromatic ring-fused benzimidazoles is significantly more efficient than literature radical protocols using chemical initiators, although 2-iodo-1-(ω-pyridin-2-ylalkyl)-1H-benzimidazoles preferentially undergo a nucleophilic ipso-substitution
Synthesis of novel benzimidazole salts and microwave-assisted catalytic activity of in situ generated Pd nanoparticles from a catalyst system consisting of benzimidazol salt, Pd(OAc)$_{{2}}$, and base in a Suzuki-Miyaura reaction
Novel benzimidazolium salts having N-benzyl or N-(4-substitutedbenzyl) groups were synthesized and their microwave-promoted catalytic activity for the Suzuki--Miyaura cross-coupling reaction were determined using in situ formed palladium(0) nanoparticles (PdNPs) from a catalytic system consisting of Pd(OAc)_2/K2CO_3 in DMF/H_2O. PdNPs were characterized by X-ray diffraction (XRD) pattern and particle size of in situ generated PdNPs from the Pd(111) plane was determined to be of diameter 19.6 nm by the Debye--Scherrer equation. Moreover, the yield of the Suzuki--Miyaura reactions with aryl iodides and aryl bromides was found to be nearly quantitative. The synthesized benzimidazole salts (1--5) were identified by ^1H and ^13}C NMR and IR spectroscopic methods, and micro analysis. The molecular structure of 5 was also determined by X-ray crystallography.
2-Arylazocarboxylate and 2-arylazocarboxamide derivatives can serve as replacements of typical Mitsunobu reagents such as diethylazodicarboxylate. A systematic investigation of the reactivity and physical properties of those azo compounds has revealed that they have an excellent ability as Mitsunobu reagents. These reagents show similar or superior reactivity as compared to the known azo reagents
The catalytic effects of in situ prepared N-heterocyclic carbenes from benzimidazole salts in Suzuki–Miyaura cross-coupling reaction and uses in catalytic preparation of 1,3,5-triphenyl-1,3,5-triazinane-2,4,6-trione from phenyl isocyanate
作者:Ülkü YILMAZ、Hasan KÜÇÜKBAY
DOI:10.3906/kim-1804-39
日期:——
including Pd(OAc)2 and the base in the Suzuki– Miyaura cross-coupling reaction under microwave irradiation. They were also used as catalysts in the cyclotrimerization of phenylisocyanate to yield 1,3,5-triphenyl-1,3,5-triazinane-2,4,6-trione. It has been observed that benzimidazole salts made a positive contribution to both catalytic reactions as a NHC precursor.
合成了许多带有3-苯基丙基取代基(1a-1h)的苯并咪唑盐,并通过1 H NMR,13 C NMR,IR光谱法和元素分析鉴定了它们的结构。这些N-杂环卡宾(NHC)前体在微波辐射下被用作Sduki-Miyaura交叉偶联反应中包括Pd(OAc)2和碱的催化体系的一部分。它们还用作异氰酸苯酯的环三聚反应的催化剂,得到1,3,5-三苯基-1,3,5-三嗪烷-2,4,6-三酮。已经观察到,苯并咪唑盐作为NHC前体对两种催化反应均具有积极作用。