Chemoselectivities in the Platinum-Catalyzed Hydrative Carbocyclizations of Oxo-Alkyne-Nitrile Functionalities
作者:Anupam Mukherjee、Rai-Shung Liu
DOI:10.1021/ol1029047
日期:2011.2.18
Two new hydrativecarbocyclizations of oxa-alkyne-nitrile functionalities are reported to produce distinct nitrogen-containing heterocycles. Protracted heating of oxoalkynyl nitrile substrates with PtCl2/CO/H2O in hot 1,4-dioxane gave 2,3-dihydro-1H-pyrido[1.2-b]-isoquinolin-4(6H)-ones. In this hydration reaction, dicarbonyl nitrile intermediates were isolated efficiently after a brief period, and
据报道,氧-炔烃-腈官能团的两个新的水合碳环化反应产生了独特的含氮杂环。在热的1,4-二恶烷中用PtCl 2 / CO / H 2 O长时间加热氧代炔基腈底物,得到2,3-二氢-1 H-吡啶基[1.2 - b ]-异喹啉-4(6 H)-。在该水合反应中,短暂地有效分离出二羰基腈中间体,然后将其进行基于NHC的交叉安息香偶合,得到螺环醇,并进一步与TfOH反应生成螺环[indene-2,2'-哌啶]。-1,6 ′(3 H)-二酮。
A strategy for the preparation of cyclic polyarenes based on single electron transfer-promoted photocyclization reactions
作者:Hea Jung Park、Jung Hei Choi、Byeol Na Park、Ung Chan Yoon、Dae Won Cho、Patrick S. Mariano
DOI:10.1007/s11164-011-0422-8
日期:2012.3
Single electron transfer (SET)-promoted photocyclization reactions of substrates comprised of benzylsilane tethered to phthalimides were subjected to an exploratory study in order to probe a new approach for the preparation of cyclic polyarenes. The results show that UV irradiation of the substrates leads to efficient photochemical reactions that are initiated by SET from benzylsilane moieties to the excited phthalimide acceptor. Ensuing desilylation reactions of the benzylsilane cation radical moieties in the intermediate zwitterionic biradicals and proton transfer gives biradical precursors of the cyclic polyarene products. The observations made in this effort suggests that SET photochemical methods, which have been employed earlier to generate cyclic poly-ethers, -thioethers and -amides, serve as a useful method to access potentially interesting macrocyclic targets.
Reductive intramolecular coupling of phthalimides with esters and ketones by low-valent titanium
作者:Naoki Kise、Tatsuhiro Manto、Toshihiko Sakurai
DOI:10.1016/j.tet.2020.131725
日期:2020.12
The reductive intermolecular coupling of phthalimides with esters by low-valenttitanium gave five-, six-, and seven-membered cyclized products as α-hydroxyketones and their further reduced ketones. The obtained cyclized products were transformed to alkylideneisoindolin-1-ones. The reductive intermolecular coupling of phthalimides with ketones by low-valenttitanium also gave five-, six-, and seven-membered