Two C–O Bond Formations on a Carbenic Carbon: Palladium-Catalyzed Coupling of <i>N</i>-Tosylhydrazones and Benzo-1,2-quinones To Construct Benzodioxoles
A novel and efficient method for the formation of two C–O bonds on a carbenic carbon is reported. This palladium-catalyzed coupling of N-tosylhydrazones and benzo-1,2-quinones were involved the process of carbonylylidesgeneration, aromatization, and intramolecular nucleophilic addition, delivering various useful benzodioxoles in high yields.
silica is investigated. The Mn sites mimic the manganese-dependent dioxygenase (MndD), which is an enzyme that catalyses the oxidation of catechol derivatives. The metal complexes were introduced in the silica using a dinuclear complex [Mn2L2(Cl)2(μ-Cl)2] as a precursor with a clickable ligand N,N′-bis[(pyridin-2-yl)methyl]prop-2-yn-1-amine (L). Azide moieties covalently grafted on MCM-41 type mesoporous
研究了一种混合生物启发的材料,该材料具有在介孔结构的多孔二氧化硅表面上接枝了锰(Ⅱ)配合物的材料。Mn位点模仿锰依赖性双加氧酶(MndD),后者是一种催化邻苯二酚衍生物氧化的酶。使用双核络合物[Mn 2 L 2(Cl)2(μ-Cl)2 ]作为前体具有可点击的配体N,N'-双[(吡啶-2-基)甲基] prop-2-yn-1-胺(L)。共价接枝在MCM-41型介孔二氧化硅上的叠氮化物部分用于利用CuBr(PPh 3)通过Huisgen环加成固定锰配合物)3作为催化剂。第二个官能团-三甲基甲硅烷基或吡啶-接枝在二氧化硅上,以与纳米孔尺寸限制一起带来与MndD中相似的金属环境。掺入锰配合物后,材料的介观结构得以保持。3,5-二-催化氧化吨发生丁基儿茶酚(3,5- DTBC)插入醌,而不需要在金属配合物中的多孔固体,所限制的额外的碱。相比之下,与分子类似物相反,总是需要碱性介质的4-叔丁基邻苯二酚(4-TBC)氧化导致全部氧化成邻醌。
[3+1+1] Annulation Reaction of Benzo‐1,2‐Quinones, Aldehydes and Hydroxylamine Hydrochloride: Access to Benzoxazoles with Inorganic Nitrogen Source
作者:Fulin Chen、Chuanle Zhu、Huanfeng Jiang
DOI:10.1002/adsc.202001521
日期:2021.4.13
By employing large‐tonnage industrial feedstock inorganic hydroxylaminehydrochloride as the nitrogen source, its [3+1+1] annulation reaction with benzo‐1,2‐quinones and aldehydes delivers various useful benzoxazoles in high yields. Preliminary mechanistic studies prove that the quinone oxime rather than the aldehyde oxime is the reaction intermediate.
Amine oxidation and the chemistry of quinone imines. Part III. 2,4-Di-methoxy-5-t-butylaniline
作者:R. K. Haynes、F. R. Hewgill
DOI:10.1039/p19720000813
日期:——
isomeric phenoxazone (12). These reactions exemplify a new synthesis for phenoxazones. Other products isolated from the oxidation of the aniline (1) are the p-quinone (5), the quinone imine (7), and the two N-aryl-p-quinone imines (6) and (8).
Polypeptides having beta-glucosidase activity and polynucleotides encoding same
申请人:Morant Marc D.
公开号:US20120023623A1
公开(公告)日:2012-01-26
The present invention relates to isolated polypeptides having beta-glucosidase activity and isolated polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.