Diastereodivergent Synthesis of Hexahydro‐6
<i>H</i>
‐benzo[
<i>c</i>
]chromen‐6‐one Derivatives Catalyzed by Modularly Designed Organocatalysts
作者:Satish Jakkampudi、Ramarao Parella、Hadi D. Arman、John C.‐G. Zhao
DOI:10.1002/chem.201806447
日期:2019.6.4
hexahydro‐6H‐benzo[c]chromen‐6‐one derivatives with good to high diastereoselectivities (up to 98:2 d.r.) and enantioselectivities (up to >99 % ee) has been achieved by using a domino Michael/Michael/hemiacetalization reaction between trans‐2‐hydroxy‐β‐nitrostyrenes and trans‐7‐oxo‐5‐heptenals followed by oxidation. With use of appropriate modularly designed organocatalysts (MDOs) that are self‐assembled
使用多米诺·迈克尔(Domino Michael)可实现非对映异构合成具有良好到高非对映选择性(高达98:2 dr)和对映选择性(高达> 99%ee)的六氢-6 H-苯并[ c ]铬n-6-one衍生物。反式-2-羟基-β-硝基苯乙烯与反式-7-氧代-5-庚烯之间的/ Michael /半缩醛化反应,然后氧化。通过使用适当的模块化设计的有机催化剂(MDO),这些有机催化剂是从氨基酸衍生物和金鸡纳生物碱衍生物就地自组装而成的,从中获得了所需的六氢-6 H-苯并[ c ]铬6-6-1的两种不同的非对映异构体。相同的基材。
Asymmetric Catalysis Using Modularly Designed Organocatalysts: Synthesis of Fused Tricyclic Pyrano‐Pyrano[2,3‐
<i>c</i>
]pyrrol Derivatives
A highly enantioselective organocatalytic Michael addition‐acetalation/oxa‐Michael reaction involving aldehydes and dioxopyrrolidines has been discovered. The asymmetric reaction is mediated by modularly designed organocatalysts (MDOs) self‐assembled from cinchonaalkaloidderivatives and amino acids providing a range of optically active tricyclic hexahydro‐2H‐pyrano[3′,2′:5,6]pyrano[2,3‐c]pyrrol derivatives
已发现涉及醛和二氧杂吡咯烷的高度对映选择性的有机催化迈克尔加成缩醛/ oxa-Michael反应。不对称反应是由金鸡纳生物碱衍生物和氨基酸自组装而成的模块化设计的有机催化剂(MDO)介导的,提供一系列光学活性的三环六氢-2 H-吡喃[3',2':5,6]吡喃[2,在温和的反应条件下,3- c ]吡咯衍生物的收率高(高达99%),对映选择性很好(至ee高达99%)。
Domino Michael/Michael reaction catalyzed by switchable modularly designed organocatalysts
The domino Michael/Michael reaction between (E)-7-aryl-7-oxohept-5-enals and trans-cinnamaldehydes was investigated by using modularlydesignedorganocatalysts (MDOs). It was found that both the enamine and iminium catalytic modes of the MDOs are switchable and can be individually switched on and off by using appropriate combinations of the precatalyst modules and the reaction conditions. When both the
Stereoselective synthesis of spirooxindole derivatives using an organocatalyzed tandem Michael–Michael reaction
作者:Huicai Huang、Manisha Bihani、John C.-G. Zhao
DOI:10.1039/c5ob02348c
日期:——
A highly efficient stereoselective method for the synthesis of functionalized spirooxindole derivatives with three stereogenic centers was realized through an organocatalytic tandem Michael–Michael reaction. By employing (S)-α,α-diphenylprolinol trimethylsilyl ether as the catalyst and N,N′-bis[3,5-bis(trifluoromethyl)phenyl]thiourea as the cocatalyst, the reaction between N-tritylisatylidenemalononitriles
One-Pot Sequential Organocatalysis: Highly Stereoselective Synthesis of Trisubstituted Cyclohexanols
作者:Qipu Dai、Hadi Arman、John Cong-Gui Zhao
DOI:10.1002/chem.201203104
日期:2013.1.28
>99:1) and enantioselective (ee value up to 96 %) synthesis of trisubstituted cyclohexanols was achieved by using a one‐pot sequentialorganocatalysis that involved a quinidine thiourea‐catalyzed tandem Henry–Michael reaction between nitromethane and 7‐oxo‐hept‐5‐en‐1‐als followed by a tetramethyl guanidine (TMG)‐catalyzed tandem retro‐Henry–Henry reaction on the reaction products of the tandem Henry–Michael