Cyclization of alk-4-ynals with o-diaminoarenes as a selective one-pot synthesis of arylmethylidene-substituted 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazoles and 7,8-dihydro-6H-pyrrolo[1’,2’:1,2]imidazo[4,5-b]pyridines
- 作者: Gvozdev V.1, Shavrin K.1, Baskir E.1, Egorov M.1, Nefedov O.1
-
隶属关系:
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
- 期: 卷 65, 编号 7 (2016)
- 页面: 1829-1838
- 栏目: Full Articles
- URL: https://journals.rcsi.science/1066-5285/article/view/238607
- DOI: https://doi.org/10.1007/s11172-016-1517-6
- ID: 238607
如何引用文章
详细
A one-pot synthesis of arylmethylidene-substituted 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazoles based on the reaction of alk-4-ynals with 1,2-diaminobenzenes in DMSO at sequential catalysis with NH4Br and bases was suggested. The use in these processes of KOH as a base led to the selective formation of E-isomers of the final products in 48–66% yields, whereas less basic K2CO3 gave the corresponding Z-isomers in 32–82% yields. Similar cyclization reactions involving 2,3-diaminopyridine gave 7,8-dihydro-6H-pyrrolo[1’,2’:1,2]imidazo[4,5-b]pyridines in up to 56% yields. The distinguishing feature of the processes under study is proceeding of their key step that is intramolecular hydroamination of the triple bond, as a 5-exo-dig-cyclization. The necessity for the application of drastic conditions required for these processes is in agreement with the results of quantum chemical calculations of PES of their most probable rate-determining step, namely, the cyclization of the corresponding benzimidazolide anions to cyclic vinyl anions.
作者简介
V. Gvozdev
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
编辑信件的主要联系方式.
Email: vgvozdev2006@yandex.ru
俄罗斯联邦, 47 Leninsky prosp., Moscow, 119991
K. Shavrin
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Email: vgvozdev2006@yandex.ru
俄罗斯联邦, 47 Leninsky prosp., Moscow, 119991
E. Baskir
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Email: vgvozdev2006@yandex.ru
俄罗斯联邦, 47 Leninsky prosp., Moscow, 119991
M. Egorov
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Email: vgvozdev2006@yandex.ru
俄罗斯联邦, 47 Leninsky prosp., Moscow, 119991
O. Nefedov
N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences
Email: vgvozdev2006@yandex.ru
俄罗斯联邦, 47 Leninsky prosp., Moscow, 119991