Facile, One-Step Production of Niacin (Vitamin B3) and Other Nitrogen-Containing Pharmaceutical Chemicals with a Single-Site Heterogeneous Catalyst
作者:Robert Raja、John Meurig Thomas、Michael Greenhill-Hooper、Steven V. Ley、Filipe A. Almeida Paz
DOI:10.1002/chem.200701679
日期:2008.3.7
Niacin (3-picolinic acid), which is extensively used as vitaminB3 in foodstuffs and as a cholesterol-lowering agent, along with other oxygenated products of the picolines, 4-methylquinoline, and a variety of pyrimidines and pyridazines, may be produced in a single-step, environmentally benign fashion by combining single-site, open-structure, heterogeneouscatalysts with a solid source of active oxygen
A one-pot, two-stepsynthesis of pyridine-2-ylmethyl thioethers is developed through a TFAA-mediated [3,3]-sigmatropic rearrangement of pyridine N-oxides and TBAB-catalyzed direct conversion of trifluoroacetates into thioethers under metal- and base-free conditions. This methodology enables thiolation of the unactivated methyl C(sp3)–H bond in 2-picolines with thiols. Remarkable features of the method
The versatility of non-heme diiron monooxygenase PmlABCDEF: a single biocatalyst for a plethora of oxygenation reactions
作者:Vytautas Petkevičius、Justas Vaitekūnas、Mikas Sadauskas、Fabian Peter Josef Schultes、Dirk Tischler、Rolandas Meškys
DOI:10.1039/d2cy01167k
日期:——
(such as styrenes and allylic ethers) produced epoxide derivatives (oxiranes). Highly valued compounds including benzyl glycidyl ether and phenyl glycidyl ether were prepared with pronounced enantiomeric excess – 93% and 77% respectively. Phenolic compounds underwent ortho-directed aromatic ring hydroxylation reactions, yielding catechol derivatives such as 3-methylcatechol, 3-ethylcatechol, and 3-chlorocatechol
在本文中,我们讨论了非血红素二铁单加氧酶 PmlABCDEF 及其突变体在各种不同氧化反应中的应用。带有 PmlABCDEF 单加氧酶及其变体的恶臭假单胞菌KT2440的全细胞被证明是用于环羟基化、杂原子氧化和 C C 键功能化的多功能生物催化剂。N-杂芳族化合物如吡啶、吡嗪和嘧啶被转化为相应的N-氧化物在高底物负载下,在一些情况下,具有良好的区域选择性。芳族硫醚转化为亚砜作为反应的主要产物。吲哚的生物氧化导致靛蓝色素的形成,即靛蓝衍生物。用含有双键的取代基(如苯乙烯和烯丙基醚)的芳族化合物转化产生环氧化物衍生物(环氧乙烷)。制备高价值的化合物,包括苄基缩水甘油醚和苯基缩水甘油醚,对映体明显过量——分别为 93% 和 77%。酚类化合物经过邻位-定向芳环羟基化反应,产生儿茶酚衍生物,例如 3-甲基儿茶酚、3-乙基儿茶酚和 3-氯儿茶酚。总体而言,我们证明了 (1) PmlABCDEF 单加
Some Diazine-N-oxides<sup>1</sup>
作者:C. F. KOELSCH、WILLIAM H. GUMPRECHT
DOI:10.1021/jo01105a003
日期:1958.11
Pyrazines. I. Pyrazine-N-oxides. Preparation and Spectral Characteristics<sup>1</sup>