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
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
作者:Rajnikanth Sunke、P. Vijaya Babu、Swapna Yellanki、Raghavender Medishetti、Pushkar Kulkarni、Manojit Pal
DOI:10.1039/c4ob01268b
日期:——
We report a true MCR involving the reaction of N-(prop-2-ynyl)quinoxalin-2-amine derivatives with 2-iodoanilines and tosyl azide in the presence of 10 mol% of CuI and Et3N in DMSO to afford the pre-designed hybrid molecules containing quinoxaline framework linked with a benzimidazole nucleus. The MCR proceeds in the absence of any ligand and/or lateral addition of the catalyst/base affording products within 30 min in good yields, some of which showed encouraging apoptosis inducing properties in zebrafish.
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。
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.