Enantioselective phospha-Michael reaction of diethyl phosphonate with exocyclic α,β-unsaturated benzocyclic ketones catalyzed by a dinuclear zinc−AzePhenol catalyst
作者:Na Shao、Yong-Yang Luo、Hui-Jie Lu、Yuan-Zhao Hua、Min-Can Wang
DOI:10.1016/j.tet.2018.03.016
日期:2018.4
The dinuclear zinc complexes as high performance catalysts were used to catalyze phospha-Michael reaction of exocyclic α,β-unsaturated benzocyclic ketones under mild conditions, and the desired products possessing 1-indanones or 1-tetralones skeleton were obtained with excellent enantioselectivities of up to 99%/99% ee and yields of up to 99%. The absolute stereochemistry of the major products catalyzed
Evaluation of Silica-H2SO4 as an Efficient Heterogeneous Catalyst for the Synthesis of Chalcones
作者:Aeysha Sultan、Abdul Raza、Muhammad Abbas、Khalid Khan、Muhammad Tahir、Nazamid Saari
DOI:10.3390/molecules180810081
日期:——
We report an efficient silica-H2SO4 mediated synthesis of a variety of chalcones that afforded the targeted compounds in very good yield compared to base catalyzed solvent free conditions as well as acid or base catalyzed refluxing conditions.
Synthesis of fused cyanopyrroles and spirocyclopropanes via addition of N-ylides to chalconimines
作者:Siba Prasad Midya、Elumalai Gopi、Nishikant Satam、Irishi N. N. Namboothiri
DOI:10.1039/c7ob00529f
日期:——
Addition of N-ylides derived from DABCO to chalconimines takes place through a Michael addition–cyclization pathway to afford fused cyanopyrroles and/or spirocyclopropanes. The product profile depends heavily on the nature of chalconimines. While 6-membered cyclic chalconimines provide a mixture of pyrrole and spirocyclopropane, 5-membered chalconimines furnish exclusively spirocyclopropane. Cyclopropane
Stereoselective [4 + 3] annulation of azadienes and ethyl 4-bromo-3-oxobutanoate: construction of benzindeno-fused azepine derivatives
作者:Jinhui Shen、Aimin Yu、Xiangtai Meng
DOI:10.1039/d1ob01749g
日期:——
compounds. This work reported a NaH-promoted cycloaddition between azadienes and ethyl 4-bromo-3-oxobutanoate, which delivered a series of benzindenoazepines with good yields and stereoselectivities. Such benzindenoazepine derivatives were not easily obtained by using a traditional approach. The application of this cycloaddition strategy has been extended to azadienes bearing a benzofuran or benzothiophene
苯并二氮杂环系统是一种有吸引力的生物活性化合物支架。这项工作报道了 NaH 促进的氮杂二烯和 4-溴-3-氧代丁酸乙酯之间的环加成反应,产生了一系列具有良好收率和立体选择性的苯并二氮杂卓。使用传统方法不容易获得此类苯并二氮杂卓衍生物。这种环加成策略的应用已扩展到带有苯并呋喃或苯并噻吩部分的氮杂二烯。通过克级实验和产品的合成转化展示了该方法的实用性。
Michael addition of malononitrile to indenones: Synthesis and characterization of 2-(1-oxo-2,3-dihydro-1<i>H</i>-inden-2-yl) (aryl)(methyl)malononitrile derivatives
ABSTRACT Indanones 3 were prepared from the reaction of indanone (1) with corresponding benzaldehyde derivatives 2, as described in the literature. Then, indenones 3 were subjected to KOtBu-catalyzed Michael addition with malononitrile to give a mixture of diastereomers 5 with a low conversion and no diastereoselection. Utilization of phase-transfer catalyst such as benzyltriethylammonium chloride