Total Synthesis of 7- and 8-Oxygenated Pyrano[3,2-<i>a</i>]carbazole and Pyrano[2,3-<i>a</i>]carbazole Alkaloids via Boronic Acid-Catalyzed Annulation of the Pyran Ring
作者:Konstanze K. Julich-Gruner、Olga Kataeva、Arndt W. Schmidt、Hans-Joachim Knölker
DOI:10.1002/chem.201403143
日期:2014.7.7
The boronic acid‐catalyzed annulation of citral opens up a short route to oxygenated cyclized monoterpenoid pyranocarbazole alkaloids. Thus, murrayamine‐D is available in only three steps and 55% overall yield from the corresponding carbazole precursor.
2,2′‐Bis(arylamino)‐1,1′‐biaryls as Building Blocks for the Synthesis of Dibenzo[<i>d</i>,<i>f</i>][1,3]diazepines, Dibenzo[<i>d</i>,<i>f</i>][1,3]diazepinones, and Dibenzo[<i>c</i>,<i>e</i>][1,2,7]thiadiazepine 6‐Oxides
block: A versatile synthesis of several seven-membered heterocyclic ring systems is described. Key steps of our approach are the iron-catalyzed oxidative C−C homocoupling of diarylamines to 2,2′-bis(arylamino)-1,1′-biaryls and their subsequent condensation with 1,1-dielectrophiles to 6,7-dihydrodibenzo[d,f][1,3]diazepines, 5,7-dihydrodibenzo[d,f][1,3]diazepinones, and 5,7-dihydrodibenzo[c,e][1,2,7]thiadiazepine
一个中心构件:描述了几种七元杂环系统的通用合成。我们方法的关键步骤是二芳基胺与 2,2'-双(芳基氨基)-1,1'-联芳基的铁催化氧化 C−C 自偶联,以及随后与 1,1-二亲电子试剂缩合成 6,7-二氢二苯并[ d , f ][1,3]二氮杂卓类、5,7-二氢二苯并[ d , f ][1,3]二氮杂酮类和 5,7-二氢二苯并[ c , e ][1,2,7]硫杂氮杂卓 6-氧化物。