Preparation of (E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-ones as Fluorinated Building Blocks and Their Application in Ready and Highly Stereoselective Routes to trans-2,3-Dihydrofurans Substituted with Trifluoromethyl and Sulfonyl Groups
作者:Haigang Yu、Jing Han、Jie Chen、Hongmei Deng、Min Shao、Hui Zhang、Weiguo Cao
DOI:10.1002/ejoc.201200180
日期:2012.6
(E)-4-Aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-one fluorinatedbuildingblocks were prepared through a two-step process. Treatment of these (E)-4-aryl-1,1,1-trifluoro-3-tosylbut-3-en-2-ones with arsonium bromides in the presence of Cs2CO3 in CH2Cl2 at reflux resulted in highlystereoselective ring closure to provide 4-tosyl-5-trifluoromethyl-trans-2,3-dihydrofurans in good to excellent yields.
Synthesis of olefins via a Wittig reaction mediated by triphenylarsine
作者:Lun Li、Jared C. Stimac、Laina M. Geary
DOI:10.1016/j.tetlet.2017.02.051
日期:2017.4
An arsine-mediated Wittigreaction for the synthesis of olefins is described. After heating triphenylarsine in the presence of an activated alkyl bromide for 30 minutes, the resulting arsonium salt condensed with aldehydes in as little as 5 minutes at room temperature, yielding the olefins in high yields. Aromatic, heteroaromatic, and alkyl aldehydes were all suitable substrates for this process.
Reaction of Phenacyltriphenylarsonium Bromides with<i>N</i>-Methylaniline and<i>N</i>,<i>N</i>-Dimethylaniline
作者:Raj Kumar Bansal、Gope Bhagchandani
DOI:10.1246/bcsj.53.2423
日期:1980.8
Reaction of phenacyltriphenylarsonium bromide with N-methylaniline furnished 2-phenylindole predominantly together with 1-methyl-2-phenylindole. The corresponding reaction of the arsonium salt with N,N-dimethylaniline did not give any indole, instead a simple nucleophilic substituted product, α-4′-(dimethylamino)deoxybenzoin was obtained. But, the latter reaction on being carried out in presence of hydrobromic acid afforded 1-methyl-2-phenylindole by the demethylation of N,N-dimethylaniline.
A highlystereoselectivesynthesis of exo-spiro[cyclopropane-1,4′-pyrazolin-5′-one] from 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one and arsonium bromide in the presence of base has been achieved. The triphenylarsine-catalyzed cyclopropanation of 4-arylidene-3-methyl-1-phenyl-pyrazolin-5-one with bromide in the presence of NaHCO3 has also been studied. Both exo and endo isomers were formed in this
在碱存在下,由4-亚芳基-3-甲基-1-苯基-吡唑啉-5-酮和溴化砷高度立体选择性地合成exo -spiro [cyclopropane-1,4'-pyrazolin-5'-one]实现了。在NaHCO 3存在下,还研究了三苯ar催化四溴化亚芳基-3-甲基-1-苯基-1-吡唑啉-5-酮的环丙烷化反应。两个外和内切形成在该反应中的异构体。产物的结构通过IR,MS,1 H NMR,元素分析和X射线衍射分析来表征。