Metal-Free Diastereo- and Enantioselective Dearomative Formal [3 + 2] Cycloaddition of 2-Nitrobenzofurans and Isocyanoacetate Esters
作者:Adrian Laviós、Amparo Sanz-Marco、Carlos Vila、M. Carmen Muñoz、José R. Pedro、Gonzalo Blay
DOI:10.1021/acs.orglett.2c00427
日期:2022.3.25
The diastereo- and enantioselective dearomative formal [3 + 2] cycloaddition of 2-nitrobenzofurans and α-aryl-α-isocyanoacetate esters provides tricyclic compounds bearing the 3a,8b-dihydro-1H-benzofuro[2,3-c]pyrrole framework with three consecutive stereogenic centers. The reaction was enabled by a cupreine-ether organocatalyst. The reaction products were obtained with almost full diastereoselectivity
2-硝基苯并呋喃和α-芳基-α-异氰基乙酸酯的非对映和对映选择性脱芳香形式[3 + 2]环加成得到带有3 a ,8 b -二氢-1 H -苯并呋喃[2,3- c ]的三环化合物具有三个连续立体中心的吡咯框架。该反应是通过铜醚有机催化剂实现的。获得的反应产物具有几乎完全的非对映选择性,并且对于许多取代的2-硝基苯并呋喃和异氰乙酸酯具有优异的对映体过量。
Nucleophilic Dearomatization of 3-nitrobenzofurans by the Action of 2-(1-arylethylidene)Malononitriles
作者:Dmitry V. Osipov、Darya А. Rashchepkina、Alina А. Аrtemenko、Oleg P. Demidov、Vitaly А. Osyanin
DOI:10.1007/s10593-021-03013-2
日期:2021.10
When 2-(1-arylethylidene)malononitriles act upon 3-nitrobenzofurans in the presence of triethylamine, the furan ring opens and triethylammonium 2-aryl-1,1-dicyano-5-nitropenta-2,4-dien-1-ides are formed. The obtained salts containing the chromophoric 1,1-dicyanopentadienide fragment are of interest as anionic polymethine dyes.