phosphine-catalyzed asymmetric dearomative [3+2] cycloaddition of 2-nitrobenzofurans with aldehyde-derived Morita–Baylis–Hillman (MBH) carbonates or allenoate was developed. The reaction with MBH carbonates resulted in a series of cyclopentabenzofurans containing three contiguous stereocenters with good to high yields, diastereoselectivities and enantioselectivities. The use of allenoate also gave the target product
Palladium-Catalyzed Highly Stereoselective Dearomative [3 + 2] Cycloaddition of Nitrobenzofurans
作者:Qiang Cheng、Hui-Jun Zhang、Wen-Jun Yue、Shu-Li You
DOI:10.1016/j.chempr.2017.06.015
日期:2017.9
we report a highly stereoselective construction of tetrahydrofurobenzofurans and tetrahydrofurobenzothiophenes via palladium-catalyzed dearomative [3 + 2] cycloaddition of nitrobenzofurans and nitrobenzothiophenes, respectively. Good to excellent yields (63%–92%), diastereoselectivity (13/1 → >20/1 dr), and enantioselectivity (75%–95% ee) were obtained, leading to products with vicinal stereogenic
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。
Asymmetric dearomatization of 2-nitrobenzofurans by organocatalyzed one-step Michael addition to access 3,3′-disubstituted oxindoles
An efficient enantioselective dearomatization of 2-nitrobenzofurans was realized by organocatalyzed one-step Michael addition to access structurally diverse 3,3′-disubstituted oxindoles.
Thiol-Triggered Tandem Dearomative Michael Addition/Intramolecular Henry Reaction of 2-Nitrobenzofurans: Access to Sulfur-Containing Polyheterocyclic Compounds
thiol-triggered tandemMichael addition/intramolecular Henryreaction has been developed. A range of thiochromeno[3,2-b]benzofuran-11-ols and tetrahydrothieno[3,2-b]benzofuran-3-ols could be obtained in up to 99% yield and up to >20:1 dr. The valuable thiochromone fused benzofurans could be prepared with the reaction of 2-nitrobenzofurans and 2-mercaptobenzaldehyde via the tandem dearomative Michael addition/intramolecular
已经开发出一种通过硫醇触发的串联迈克尔加成/分子内亨利反应对 2-硝基苯并呋喃进行有效脱芳环化的方法。一系列硫代苯并[3,2- b ]苯并呋喃-11-醇和四氢噻吩并[3,2- b ]苯并呋喃-3-醇的产率高达 99%,dr 高达 >20:1。 2-硝基苯并呋喃与2-巯基苯甲醛通过串联脱芳香迈克尔加成/分子内亨利反应/重芳香化/氧化脱氢一锅两步操作制备有价值的硫色酮稠合苯并呋喃。初步提出了该反应的机理。