Weak Lewis acid for high nucleophilicity: Hydridoborate derived from B(2,6‐F2C6H3)3 shows significant hydride character. Solid‐state and solution structure analysis revealed a dihydrogen‐bonded aggregate. The new frustratedLewispair was applied in the hydrogenation of nitroolefins and acrylates (see scheme; EWG=electron‐withdrawing group). The decreased Lewis acidity provides higher reactivity and
弱路易斯酸,具有高亲核性:衍生自B(2,6-F 2 C 6 H 3)3的氢硼酸盐显示出显着的氢化物特征。固态和溶液结构分析表明,存在氢键结合的聚集体。新的受阻的路易斯对用于硝基烯烃和丙烯酸酯的氢化反应(参见方案; EWG =吸电子基团)。降低的路易斯酸度可提供更高的反应性和官能团耐受性。
C3-Symmetric Proline-Functionalized Organocatalysts: Enantioselective Michael Addition Reactions
作者:Jarugu Narasimha Moorthy、Satyajit Saha
DOI:10.1002/ejoc.201000569
日期:2010.11
C 3 -Symmetric, tripodal catalyst 4 based on 1,3,5-triethylbenzene, which incorporates the features of a molecular receptor, is shown to catalyze Michaeladditionreactions of carbonyl compounds to β-nitrostyrenes in a high stereoselectivity (up to 99:1 dr and up to 98 % ee).
基于 1,3,5-三乙苯的 C 3 -对称三足催化剂 4 结合了分子受体的特征,显示出以高立体选择性(高达 99: 1 dr 和高达 98 % ee)。
Diastereoselective Synthesis of Tetrahydroquinolines via [4 + 2] Annulation between in Situ Generated <i>p</i>-Quinone Methides and Nitroalkenes
作者:Junwei Wang、Xiang Pan、Jian Liu、Lin Zhao、Ying Zhi、Kun Zhao、Lihong Hu
DOI:10.1021/acs.orglett.8b02127
日期:2018.10.5
A formal [4 + 2] annulation reaction between in situ generated p-quinone methides and nitroalkenes via an aza-Michael/1,6-conjugate addition reaction sequence has been developed in which manganese dioxide is used as the oxidant to promote in situ formation of o-tosylaminophenyl-substituted p-QMs. Undermildconditions, this unprecedented cascade reaction readily occurs in good yield, providing straightforward
Catalyst-Free Efficient Aza-Michael Addition of Azoles to Nitroalkenes
作者:Pengfei Li、Fuk Kwong、Yinuo Wu、Jun Wang
DOI:10.1055/s-0031-1290359
日期:2012.3
An efficient aza-Michael addition of azole to nitroalkene has been developed. In this conjugate addition, no catalyst was employed and azole reacted with nitroolefin smoothly to afford new C-N bond adducts in good to excellent yields.
Modular synthesis of cyclic cis- and trans-1,2-diamine derivatives
作者:Anna K. Weber、Josef Schachtner、Robert Fichtler、Timo M. Leermann、Jörg M. Neudörfl、Axel Jacobi von Wangelin
DOI:10.1039/c4ob00913d
日期:——
substituted nitroarenes. Reduction with Zn/HCl provides access to various trans- and cis-diaminocyclohexenes, respectively, in a straight-forward manner. With enantiopure secondary amines, a two-step synthesis of chiral nitrocyclohexadienes was developed (82–94% ee).