Visible light mediated selective oxidation of alcohols and oxidative dehydrogenation of N-heterocycles using scalable and reusable La-doped NiWO<sub>4</sub> nanoparticles
A systematic study led to a selective synthesis of aldehydes under an argon atmosphere while the ODH of partially saturated heterocycles under an oxygen atmosphere resulted in very good to excellent yields. The methodology is atom economical and exhibits excellent tolerance towards various functional groups, and broad substrate scope. Furthermore, a one-pot procedure was developed for the sequential
Reusable, homogeneous water soluble photoredox catalyzed oxidative dehydrogenation of N-heterocycles in a biphasic system: application to the synthesis of biologically active natural products
the substrate and catalyst at room temperature. Its potential applications to organic transformations are demonstrated by the synthesis of various biologically active N-heterocycles such as indoles, (iso)quinolines and β-carbolines and natural products such as eudistominU, norharmane, and harmane and precursors to perlolyrine and flazin. Without isolation and purification, the catalyst solution can
importance of enzyme mimics in organic synthesis inspired us to design a novel biomimetic synthesis of β-carboline alkaloids directly from tryptophan and a second amino acid. This novel one-pot protocol utilizes abundant and readily available starting materials and thus presents a green and user-friendly alternative to conventional methods that rely on stepwise synthesis. Driven by molecular iodine and TFA
DBN has been identified as an efficient reagent for promoting the dehydrogenative/decarboxylative aromatization of tetrahydro-β-carbolines under air atmosphere, to access the corresponding β-carbolines in moderate to good yields. The utility of this protocol for the gram-scale synthesis of β-carboline alkaloids eudistomin U (7) and harmane (10) has also been demonstrated.
Cu-catalyzed mild and efficient oxidation of THβCs using air: application in practical total syntheses of perlolyrine and flazin
作者:Bo Zheng、Tien Ha Trieu、Tian-Zhuo Meng、Xia Lu、Jing Dong、Qiang Zhang、Xiao-Xin Shi
DOI:10.1039/c7ra13434g
日期:——
friendliness, mildness, very good tolerance of functional groups, high yielding and easy experiment operation. In addition, this new methodology was successfully applied in the efficient and practical total syntheses of β-carboline alkaloids perlolyrine and flazin.
开发了一种通过Cu( II ) 催化氧化 1,2,3,4-四氢-β-咔啉 (THβCs)合成芳香族 β-咔啉的温和、高效和环保的方法,其中空气 (O 2 )用作清洁氧化剂。该方法具有环境友好、温和、官能团耐受性好、收率高、实验操作简单等优点。此外,该新方法成功应用于高效实用的β-咔啉生物碱perlolyrine和flalazin的全合成。