Synthesis of Carbazoles and Carbazole-Containing Heterocycles via Rhodium-Catalyzed Tandem Carbonylative Benzannulations
作者:Wangze Song、Xiaoxun Li、Ka Yang、Xian-liang Zhao、Daniel A. Glazier、Bao-min Xi、Weiping Tang
DOI:10.1021/acs.joc.6b00212
日期:2016.4.1
tri-, tetra-, and pentacyclic heterocycles from different types of aryl propargylic alcohols. These tandem reactions provide efficient access to highly substituted carbazoles, furocarbazoles, pyrrolocarbazoles, thiophenocarbazoles, and indolocarbazoles. While tricyclic heterocycles could be derived from vinyl aryl propargylic alcohols, tetra- and pentacyclic heterocycles were synthesized from diaryl
Total Synthesis of the Biscarbazole Alkaloids Murrafoline A-D by a Domino Sonogashira Coupling/Claisen Rearrangement/Electrocyclization Reaction
作者:V. Pavan Kumar、Konstanze K. Gruner、Olga Kataeva、Hans-Joachim Knölker
DOI:10.1002/anie.201305993
日期:2013.10.11
at a time? Aryl–pyran‐linked biscarbazole alkaloids of the murrafoline group (see crystal structure of murrafoline A; dark gray: C, red: O, blue: N) were accessed readily by a novel domino reaction sequence involving Sonogashira coupling, a Claisenrearrangement, and electrocyclization. The one‐pot procedure enables the straightforward synthesis of these structurally challenging alkaloids in only a
Efficient Construction of Pyrano[3,2-<i>a</i>]carbazoles: Application to a Biomimetic Total Synthesis of Cyclized Monoterpenoid Pyrano[3,2-<i>a</i>]carbazole Alkaloids
作者:Ronny Hesse、Konstanze K. Gruner、Olga Kataeva、Arndt W. Schmidt、Hans-Joachim Knölker
DOI:10.1002/chem.201301792
日期:2013.10.11
We have developed a highly efficient route to 2‐hydroxy‐3‐methylcarbazole (1) via a palladium‐catalyzed construction of the carbazole skeleton. Using 1 as relay compound, different methods for annulations of pyran rings by reaction with terpenoid building blocks have been tested. The Lewis acid promoted reaction of 1 with prenal (21) opened up an efficient route to girinimbine (3) and the corresponding
我们已经开发了一种通过钯催化的咔唑骨架构建2-羟基-3-甲基咔唑(1)的高效途径。使用1作为中继化合物,已经测试了通过与萜类结构单元反应而使吡喃环环化的不同方法。路易斯酸促进的1与醛(21)的反应开辟了一条生成吉利比滨(3)的有效途径,相应的与柠檬醛(25)的反应得到了马哈宁(5)。化合物3和5的氧化提供了murrayacine(4)和murrayacinine(6)。根据生物遗传学的建议,马哈宁(5)已被用于有效的仿生合成环化单萜吡喃并[3,2– a ]咔唑生物碱环马哈宁(7),马尼苯丁(8)和双环马哈宁(9)。的互变5,7,8和9中描述和机械影响进行了讨论。通过X射线晶体结构确定明确地验证了结构分配。此外,将环马哈宁滨(7)转化为murrayazolinine(10)和exozoline(11)。
Enantioselective Vanadium-Catalyzed Oxidative Coupling: Development and Mechanistic Insights
作者:Houng Kang、Madison R. Herling、Kyle A. Niederer、Young Eun Lee、Peddiahgari Vasu Govardhana Reddy、Sangeeta Dey、Scott E. Allen、Paul Sung、Kirsten Hewitt、Carilyn Torruellas、Gina J. Kim、Marisa C. Kozlowski
DOI:10.1021/acs.joc.8b02083
日期:2018.12.7
vanadium catalyst for enantioselectiveoxidativecoupling of phenols is reported, ultimately resulting in a simple monomeric vanadium species combined with a Brønsted or Lewis acid additive. The resultant vanadium complex is found to effect the asymmetric oxidative ortho–ortho coupling of simple phenols and 2-hydroxycarbazoles with good to excellent levels of enantioselectivity. Experimental and quantum