ABSTRACT An organocatalytic [3 + 3] benzannulation to access polysubstituted benzenes from readily available α,β-unsaturated aldehydes and 1,3-bis(phenylsulfonyl)propene or 4-sulfonylcrotonates is described. The key reaction step is considered to be the iminiumactivation of enals by a secondary aminocatalyst. This organocatalytic protocol avoids the traditional strategy which is always with the aid
benzonitriles is achieved via amino-catalyzed [3+3] benzannulation of α,β-unsaturated aldehydes and 4-arylsulfonyl-2-butenenitriles. Using pyrrolidine as an organocatalyst via iminium activation, a series of substituted benzonitriles were obtained in good to high yields in a regioselective manner. This reaction can proceed smoothly under mild reaction conditions and without the aid of any metals, additional
Enantioselective organocatalytic Michael addition of 2-arylacetates and 2-arylacetonitriles having an electron-withdrawing group to α,β-unsaturated aldehydes
作者:Seung Woo Seo、Sung-Gon Kim
DOI:10.1016/j.tetlet.2012.03.102
日期:2012.6
The asymmetric organocatalyticMichaeladdition reaction of 2-arylacetates and 2-arylacetonitriles having an electron-withdrawing group to α,β-unsaturated aldehydes has been established using diphenylprolinol trimethylsilyl (TMS) ether as organocatalyst. The 2-arylacetates and 2-arylacetonitriles having NO2-, CO2Me-, and CN-functional groups on the aromatic ring can be used in this reaction. The desired
Efficient Assembly of Polysubstituted Pyrroles via a (3 + 2) Cycloaddition/Skeletal Rearrangement/Redox Isomerization Cascade Reaction
作者:Yuanyuan Yu、Chunyu Wang、Xinze He、Xiaotong Yao、Liansuo Zu
DOI:10.1021/ol501580b
日期:2014.7.3
redox isomerization, for the synthesis of 3-allyl pyrroles is reported. In a single step, readily accessible simple starting materials are transformed into highly substituted pyrroles with high efficiency. The products obtained contain allyl substituents, which can be readily elaborated to other useful functional groups. The reaction proceeds through an unusual (3 + 2) cycloaddition/skeletal rearrangement/redox
<i>N</i>-TFA-Gly-Bt-Based Stereoselective Synthesis of Substituted 3-Amino Tetrahydro-2<i>H</i>-pyran-2-ones via an Organocatalyzed Cascade Process
作者:Liuqing Han、Ke Li、Haitong Xu、Tao Mei、Yali Sun、Jingping Qu、Yuming Song
DOI:10.1021/acs.joc.9b01488
日期:2019.8.16
excellent enantioselectivities (up to 99% ee) via an organo-catalyzed cascade procedure with N-TFA-Gly-Bt and α,β-unsaturated aldehydes as the substrates. The corresponding tetrahydro-2H-pyran-2-ones can be used for further synthetic transformations that furnish chiral-substituted 3-aminopiperidin-2-ones with high levels of stereoselectivity.