1904-73-0Relevant academic research and scientific papers
Electrophilically activated nitroalkanes in synthesis of 3,4-dihydroquinozalines
Aksenov, Alexander V.,Aksenov, Dmitrii A.,Aksenov, Nicolai A.,Grishin, Igor Yu.,Malyuga, Vladimir V.,Nobi, Mezvah A.,Rubin, Michael
, (2021/08/03)
Nitroalkanes activated with polyphosphoric acid serve as efficient electrophiles in reactions with various nucleophilic amines. Strategically placed second functionality allows for the design of annulation reactions enabling preparation of various heterocycles. This strategy was employed to develop an innovative synthetic approach towards 3,4-dihydroquinazolines from readily available 2-(aminomethyl)anilines.
Potassium tert-Butoxide-Promoted Acceptorless Dehydrogenation of N-Heterocycles
Liu, Tingting,Wu, Kaikai,Wang, Liandi,Yu, Zhengkun
supporting information, p. 3958 - 3964 (2019/08/01)
Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six- and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H2 gas in o-xylene at 140 °C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H2 gas. (Figure presented.).
Base-Promoted Synthesis of 2-Aryl Quinazolines from 2-Aminobenzylamines in Water
Chatterjee, Tanmay,Kim, Dong In,Cho, Eun Jin
, p. 7423 - 7430 (2018/07/29)
A transition-metal-free procedure for the synthesis of a highly valuable class of heteroaromatics, quinazolines, was developed by using easily available 2-aminobenzylamines and α,α,α-trihalotoluenes. The transformation proceeded smoothly in the presence of only sodium hydroxide and molecular oxygen in water at 100 °C, furnishing a variety of 2-aryl quinazolines. The crystallization process of the crude reaction mixture for the purification of the solid products circumvents huge solvent-consuming workup and column chromatographic techniques, which make the overall process more sustainable and economical.
Syntheses of 3,4- and 1,4-dihydroquinazolines from 2-aminobenzylamine
Díaz, Jimena E.,Ranieri, Silvia,Gruber, Nadia,Orelli, Liliana R.
supporting information, p. 1470 - 1477 (2017/08/02)
A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common precursor. The required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave-assisted ring closure of the corresponding aminoamides promoted by ethyl polyphosphate (PPE).
Acceptorless Dehydrogenation of N-Heterocycles by Merging Visible-Light Photoredox Catalysis and Cobalt Catalysis
He, Ke-Han,Tan, Fang-Fang,Zhou, Chao-Zheng,Zhou, Gui-Jiang,Yang, Xiao-Long,Li, Yang
supporting information, p. 3080 - 3084 (2017/03/14)
Herein, the first acceptorless dehydrogenation of tetrahydroquinolines (THQs), indolines, and other related N-heterocycles, by merging visible-light photoredox catalysis and cobalt catalysis at ambient temperature, is described. The potential applications to organic transformations and hydrogen-storage materials are demonstrated. Primary mechanistic investigations indicate that the catalytic cycle occurs predominantly by an oxidative quenching pathway.
Copper-catalyzed intermolecular cyclization of nitriles and 2-aminobenzylamine for 3,4-dihydroquinazolines and quinazolines synthesis via cascade coupling and aerobic oxidation
Li, Cheng,An, Shujuan,Zhu, Yuelu,Zhang, Jin,Kang, Yifan,Liu, Ping,Wang, Yaoyu,Li, Jianli
, p. 49888 - 49891 (2014/12/10)
A copper-catalyzed cascade coupling and aerobic oxidation of aromatic nitriles and 2-aminobenzylamine for the synthesis of 3,4-dihydroquinazolines and quinazolineshas been achieved. The catalytic system, characterized by not adding additives and using molecular oxygen as the sole oxidant, exhibited exquisite substrate specificity and operated under mild conditions through inherently green processes. This journal is
A convenient palladium-catalyzed carbonylative synthesis of quinazolines from 2-aminobenzylamine and aryl bromides
Chen, Jianbin,Natte, Kishore,Neumann, Helfried,Wu, Xiao-Feng
, p. 56502 - 56505 (2015/02/02)
A novel and practical strategy towards quinazoline scaffolds synthesis has been achieved. Through palladium-catalyzed carbonylative coupling of 2-aminobenzylamine with aryl bromides, the desired quinazolines were produced in moderate to good yields for the first time. The reactions followed an aminocarbonylation-condensation-oxidation sequence in a one-pot one-step manner. Preliminary investigation showed DMSO serves both as solvent and oxidant in this procedure.
Copper-catalyzed annulation of amidines for quinazoline synthesis
Lv, Yunhe,Li, Yan,Xiong, Tao,Pu, Weiya,Zhang, Hongwei,Sun, Kai,Liu, Qun,Zhang, Qian
supporting information, p. 6439 - 6441 (2013/08/23)
An efficient Cu-catalyzed synthesis of quinazolines via the C-N bond formation reactions between N-H bonds of amidines and C(sp3)-H bonds adjacent to sulfur or nitrogen atoms in the commonly used solvents, such as DMSO, DMF, DMA, NMP or TMEDA,
Copper-catalyzed oxidative desulfurization-promoted intramolecular cyclization of thioamides using molecular oxygen as an oxidant: An efficient route to five- To seven-membered nitrogen-containing heterocycles
Shibahara, Fumitoshi,Yoshida, Atsunori,Murai, Toshiaki
, p. 646 - 647 (2008/12/21)
Copper-catalyzed oxidative desulfurization-promoted intramolecular cyclization reactions of thioamides take place under neutral and mild conditions by using molecular oxygen as an oxidant. The process yields a wide variety of nitrogen-containing heterocyc
Formation of Hydro-1,3-diazines by the Reaction of Benzo[b]cyclohepta[e][1,4]oxazine with α,γ-Diamines
Sato, Ohki,Seshimo, Manabu,Tsunetsugu, Josuke
, p. 568 - 569 (2007/10/03)
Contrary to a report that the reaction of benzo[b]cyclohepta[e] [1,4]oxazine 1 with α,γ-diamine 2b produces 1,2,3,4-tetrahydrocyclohepta[b][1,4]diazepine 4, the product was found to be 2-phenyl-3,4,5,6-tetrahydropyrimidine 5b and is peculiar to the reaction of 1 with α,γ-diamines 2 as well as β-aminamide 7.
