Enantioselective Synthesis of Benzofuran-Fused N-Heterocycles via Chiral Squaramide Catalyzed [4 + 2] Cyclization of Azadienes with Azlactones was written by Li, Xiaoping;Yan, Juzhang;Qin, Jialiang;Lin, Shilin;Chen, Weiwen;Zhan, Ruoting;Huang, Huicai. And the article was included in Journal of Organic Chemistry in 2019.Quality Control of 3-((3,5-Bis(trifluoromethyl)phenyl)amino)-4-(((1R)-(6-methoxyquinolin-4-yl)(5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione This article mentions the following:
An asym. cyclization reaction of azadienes and azlactones was investigated by employing a Cinchona squaramide catalyst, which could afford a series of benzofuran-fused six-membered heterocycles containing a 伪,伪-disubstituted amino acid unit in a highly diastereoselective (>20:1 dr) and enantioselective (up to 99% ee) manner with good to excellent yields (up to 92%). A plausible pathway was proposed to explain the reaction process. In the experiment, the researchers used many compounds, for example, 3-((3,5-Bis(trifluoromethyl)phenyl)amino)-4-(((1R)-(6-methoxyquinolin-4-yl)(5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione (cas: 1256245-79-0Quality Control of 3-((3,5-Bis(trifluoromethyl)phenyl)amino)-4-(((1R)-(6-methoxyquinolin-4-yl)(5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione).
3-((3,5-Bis(trifluoromethyl)phenyl)amino)-4-(((1R)-(6-methoxyquinolin-4-yl)(5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione (cas: 1256245-79-0) belongs to quinuclidine derivatives. In alkane solvents quinuclidine is a Lewis base that forms adducts with a variety of Lewis acids. Traditionally, quinuclidine scaffolds can be constructed by second-order nucleophilic substitution (SN2) reaction or condensation reaction of piperidine derivatives. However, most of these reactions are racemic or chiral auxiliary-assisted processes.Quality Control of 3-((3,5-Bis(trifluoromethyl)phenyl)amino)-4-(((1R)-(6-methoxyquinolin-4-yl)(5-vinylquinuclidin-2-yl)methyl)amino)cyclobut-3-ene-1,2-dione
Referemce:
Quinuclidine – Wikipedia,
Quinuclidine | C7H13N | ChemSpider