Catalytic Enantioselective Henry Reactions of Isatins: Application in the Concise Synthesis of (
<i>S</i>
)‐(−)‐Spirobrassinin
作者:Lu Liu、Shilei Zhang、Fei Xue、Guangshun Lou、Haoyi Zhang、Shichao Ma、Wenhu Duan、Wei Wang
DOI:10.1002/chem.201101025
日期:2011.7.4
highly efficient, cupreine‐catalyzed, enantioselective Henry reaction of readily available isatins and nitroalkanes has been developed (see scheme). The products are produced in excellent yields and good enantioselectivities under mild reaction conditions and without chromatography. The utility of the strategy has been demonstrated in the facile synthesis of (S)‐(−)‐spirobrassinin without the need for
The synthesis and characterization of copper(I) complexes of the novel pyridine‐containing macrocyclic ligand (PC‐L) and their use as catalysts in the Henry reaction are reported. The pyridine‐based 12‐membered tetraaza macrocyclic (PC‐L) ligand 1 can be obtained in good overall yield (85%) from commercially available starting materials. The Cu(I) complexes showed good catalytic activities in the Henry
for the synthesis of 3-hydroxy-3-(nitromethyl)indolin-2-one by the reaction of isatins with nitromethane/nitroethane in the presence of DABCO. The reaction is catalytic, very rapid, yields are very high and avoids the use of solvents for reaction. The protocol is applicable for substituted isatins as well as substituted nitroalkanes.
Vinylogous Michael addition of nitroalkylideneoxindoles to isatylidene-malononitriles in the regio- and diastereoselective synthesis of dispirocyclopentylbisoxindoles
作者:Lakshminarayana Satham、Chenikkayala Siva Sankara、Shweta Bhagat、Irishi N N Namboothiri
DOI:10.1007/s12039-022-02122-5
日期:——
isatilydene-malononitriles, triggered by a vinylogous Michaeladdition, leads to 1,2-dispiro-bisoxindoles with three contiguous stereocenters. This regioselective cascade reaction also takes place in good to excellent yields and with complete stereoselectivity. The experimental results are supported by DFT calculations, including transitionstate energy calculations, using the B3LYP/6-31+g(d,p) basis
Triton B Catalyzed Rapid and Mild Synthetic Protocol for both Henry Reaction of Isatin and Michael Reaction of Chalcone with Nitroalkane
作者:Eeshwaraiah Begari、Mrinal Talukdar、Nasreen Islam、Akanksha Mishra、Alpa Y Dave
DOI:10.1055/s-0043-1774862
日期:——
hydroxide) and isatins and chalcones, respectively. This methodology is inexpensive, the reagents are easy to handle, and the approach offers wide functional group tolerance of isatins and chalcones. The base catalyst Triton B is less toxic, recyclable, and reusable. This efficient method reduces reaction times, minimizes reagent excess, avoids chromatography, and is aligned with sustainable chemistry principles
分别使用无金属催化剂 Triton B(氢氧化苄基三甲基铵)以及靛红和查耳酮,开发了亨利反应和迈克尔反应的高效通用合成方案。该方法价格低廉,试剂易于处理,并且该方法对靛红和查耳酮具有广泛的官能团耐受性。碱性催化剂 Triton B 毒性较小、可回收、可重复使用。这种高效的方法减少了反应时间,最大限度地减少了试剂过量,避免了色谱法,并且符合可持续化学原理,为不同行业提供了环保应用。