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
A one-pot electronically controlled [4 + 2] cycloaddition reaction of in situ generated benzyne with 2-arylidene-1-indenone is unveiled to construct novel spirocyclic frameworks in a regio- and diastereoselective fashion. This protocol features operational simplicity, good functional group tolerance and avoids the use of metal catalysts and external additives. This methodology has extended the synthetic
揭示了原位生成的苯与 2-亚芳基-1-茚酮的单锅电子控制 [4 + 2] 环加成反应,以区域和非对映选择性方式构建新型螺环框架。该协议具有操作简单、良好的官能团耐受性并避免使用金属催化剂和外部添加剂的特点。这种方法扩展了 2-arylidene-1-indenones 的合成应用,可以轻松获得有价值的 10' H -spiro[indene-2,9'-phenanthren]-1(3 H )-ones 并获得高产率。
A regioselective [3 + 2] cycloaddition reaction of 2-benzylidene-1-indenones with functional olefins to access indanone-fused 2D/3D skeletons
作者:Yi-Hang Deng、Chuan-Bao Zhang、Jun-Jie Sun、Wen-Li Xu、Ji-Ya Fu
DOI:10.1039/d3ob00559c
日期:——
The regioselective [3 + 2] cycloadditionreaction of 2-benzylidene-1-indenones with functional olefins was established with DABCO as a base under mild conditions. Using this approach, a series of diversely substituted indanone-fused cyclopentane polycycles with highly crowded multiple substituents were synthesized in high yields.