Ligand-free MCR for linking quinoxaline framework with a benzimidazole nucleus: a new strategy for the identification of novel hybrid molecules as potential inducers of apoptosis
AlCl3 induced C–N bond formation followed by Pd/C–Cu mediated coupling–cyclization strategy: synthesis of pyrrolo[2,3-b]quinoxalines as anticancer agents
作者:Bagineni Prasad、K. Shiva Kumar、P. Vijaya Babu、K. Anusha、D. Rambabu、Ajit Kandale、G.R. Vanaja、Arunasree M. Kalle、Manojit Pal
DOI:10.1016/j.tetlet.2012.08.119
日期:2012.11
affording a convenient method for the preparation of N-aryl substituted 3-chloroquinoxalin-2-amines. A related N-benzyl derivative, however, was prepared via a conventional method. These N-alkyl/aryl substituted 3-chloroquinoxalin-2-amines on coupling with terminal alkynes in toluene under Pd/C–Cu catalysis afforded a range of 1,2-disubstituted pyrrolo[2,3-b]quinoxalines within 3–5 h in good to excellent
Ligand/PTC-free intramolecular Heck reaction: synthesis of pyrroloquinoxalines and their evaluation against PDE4/luciferase/oral cancer cell growth in vitro and zebrafish in vivo
作者:P. Vijaya Babu、Soumita Mukherjee、Girdhar Singh Deora、Keerthana Sarma Chennubhotla、Raghavender Medisetti、Swapna Yellanki、Pushkar Kulkarni、Shivashankar Sripelly、Kishore V. L. Parsa、Kiranam Chatti、K. Mukkanti、Manojit Pal
DOI:10.1039/c3ob41504j
日期:——
A series of 1,3-disubstituted pyrrolo[2,3-b]quinoxalines has been designed for the potential inhibition of PDE4 without inhibiting luciferase. A ligand/PTC (phase transfer catalyst) free intramolecular Heck cyclization strategy was used to prepare these compounds, some of which showed significant inhibition of PDE4B (IC50 ≈ 5–14 μM) and growth inhibition of oral cancer cells (CAL 27) but not inhibition of luciferase in vitro. They also showed acceptable safety profiles but no apoptosis in zebrafish embryos.
Using Calcium Carbide as an Acetylene Source for Cascade Synthesis of Pyrrolo[2,3-<i>b</i>
]quinoxalines <i>via</i>
Copper-Free <i>Sonogashira</i>
Coupling Reaction
A palladium‐catalyzed cascade protocol has been established for the synthesis of 4‐methyl‐1‐(1H‐pyrrolo[2,3‐b]‐quinoxalin‐2‐yl)cyclohexanols and 2‐phenyl‐1‐(1H‐pyrrolo[2,3‐b]quinoxalin‐2‐yl)propan‐1‐ols through the reaction of N‐alkyl(aryl)‐3‐chloroquinoxalin‐2‐amines with calcium carbide and cyclohexanones or 2‐phenylpropanal. This one‐pot process, carried out without any copper salt in the key step
钯催化的级联协议已建立的4-甲基-1-(1-合成ħ吡咯并[2,3- b ] -喹喔啉-2-基)环己醇和2-苯基-1-(1- ħ -吡咯并[2,3 - b ]喹喔啉-2-基)丙-1-醇通过N-烷基(芳基)-3-氯喹喔啉-2-胺与碳化钙和环己酮或2-苯基丙醛的反应而形成。此一锅法在Sonogashira偶联反应的关键步骤中不使用任何铜盐进行,提供了一种在催化量存在下合成2,3-二取代吡咯并[2,3- b ]喹喔啉的有效方法Pd(PPh 3)2 Cl 2的含量在DMSO / H 2 O中的产率很高。该策略的好处是使用市售的,廉价的和危害较小的主要化学原料碳化钙作为湿溶剂中的乙炔源。
Quinoxaline: a new directing group for ortho C–H alkenylation / intramolecular ortho C–H cycloamination under open air leading to bioactive polynuclear N-heteroarenes
作者:Rajnikanth Sunke、Vimal Kumar、E. V. Venkat Shivaji Ramarao、Ramudu Bankala、Kishore V. L. Parsa、Manojit Pal
DOI:10.1039/c5ra14671b
日期:——
Quinoxaline has been identified as a new directing group for the Pd (or Ru)-catalyzed ortho C–H alkenylation of aniline derivatives and subsequent hypervalentiodinepromoted intramolecular ortho C–H cycloamination of the resulting N-arylquinoxalin-2-amine derivatives. This two-step strategy afforded alkenyl substituted benzo[4,5]imidazo[1,2-a]quinoxalines as inhibitors of PDE4. The Pd-catalyzed ortho
喹喔啉已被确定为苯胺衍生物的Pd(或Ru)催化邻位C-H烯基化和随后的高价碘促进的分子内邻位C-H环氨基化所得N-芳基喹喔啉-2-胺衍生物的新的导向基团。该两步策略提供了烯基取代的苯并[4,5]咪唑并[1,2- a ]喹喔啉作为PDE4的抑制剂。当发现喹啉是有效的导向基团时,苯酚衍生物的钯催化的邻位CH链烯基化也能成功进行。