Highly Diastereoselective Crown Ether Catalyzed Arylogous Michael Reaction of 3-Aryl Phthalides
作者:Marina Sicignano、Antonella Dentoni Litta、Rosaria Schettini、Francesco De Riccardis、Giovanni Pierri、Consiglia Tedesco、Irene Izzo、Giorgio Della Sala
DOI:10.1021/acs.orglett.7b02113
日期:2017.8.18
The first arylogous Michael reaction of 3-aryl phthalides has been developed. The reaction, promoted by catalytic amounts of KOH or K3PO4 and dibenzo-18-crown-6, affords the corresponding 3,3-disubstituted phthalides in good to high yields and as single diastereomers in nearly all studied cases.
已经开发了第一个3-芳基邻苯二甲酸酯的迈克尔反应。由催化量的KOH或K 3 PO 4和二苯并18-冠-6促进的反应,以几乎所有的研究情况,均以高收率和高收率提供了相应的3,3-二取代邻苯二甲酸酯。
Thermoregulated phase-transfer iridium nanoparticle catalyst: highly selective hydrogenation of the CO bond for α,β-unsaturated aldehydes and the CC bond for α,β-unsaturated ketones
作者:Wenjiang Li、Yanhua Wang、Pu Chen、Min Zeng、Jingyang Jiang、Zilin Jin
DOI:10.1039/c6cy01137c
日期:——
thermoregulated ligand Ph2P(CH2CH2O)22CH3-stabilized iridium nanoparticles exhibited a totally different orientation for the hydrogenation of unsaturated carbonyl compounds, namely, highly selective hydrogenation of the CO bond for α,β-unsaturated aldehydes and the CC bond for α,β-unsaturatedketones.
β-unsaturated ketones. Afterward, these compounds react with different commercially available ene-reductases to afford the corresponding saturated ketones. Remarkably, in the case of trisubstituted alkenes, the bioreduction reaction occurred with high stereoselectivity. Overall, a bienzymatic one-pot two-step sequential strategy has been described with respect to the synthesis of saturated ketones starting
An effective strategy for synthesis of Cu nanoparticles is designed, these nanoparticles have high catalytic activity in conjugate addition of B2(pin)2 and α,β-unsaturatedketones. The reaction of protodeboration can proceed with adding NaOtBu. In this way, a new method to reduce the conjugated alkenes of α,β-unsaturatedketones is developed with organoboranes as intermediates. Cu nanocrystals also
设计了一种有效的合成铜纳米颗粒的策略,这些纳米颗粒在B 2(pin)2和α,β-不饱和酮的共轭添加中具有高催化活性。原脱硼的反应可以通过添加NaO t Bu来进行。以这种方式,开发了一种以有机硼烷为中间体,还原α,β-不饱和酮的共轭烯烃的新方法。Cu纳米晶体在克级反应和循环利用实验中也具有优异的性能。提出了一种可能的机制。
Silazanes/catalytic bases: mild, powerful and chemoselective agents for the preparation of enol silyl ethers from ketones and aldehydes
We have developed an efficient method for the preparation of enol silyl ethers using novel agents, silazanes together with NaH or DBU catalyst, wherein TMS and TBDMS groups were smoothly and chemoselectively introduced into ketones and aldehydes under mild conditions.