In order to get further information on the effect of terminal groups on the spectral regularity of diarylpoly-ynes, we carried out the syntheses of bis(4-biphenylyl)poly-ynes (In, n=1–6) and 2,2′-difluorenylpoly-ynes (IIn, n=1–4 and 6). The bathochromic shift of the longest-wavelength absorption maxima (λL) along with the increase in n was found to be expressed by the following empirical formulas:In:λL=24
One-pot synthesis of gem-difluorostyrenes from benzyl bromide via olefination of phosphonium ylide with difluorocarbene
作者:Xiao-Yun Deng、Jin-Hong Lin、Ji-Chang Xiao
DOI:10.1016/j.jfluchem.2015.06.009
日期:2015.11
A new approach for the synthesis of gem-difluorostyrenes from benzyl bromide is described. Quaternization of triphenylphosphine with benzyl bromide to give phosphonium salts, deprotonation of the corresponding phosphonium salts to produce phosphonium ylide, and the subsequent olefination of phosphonium ylide with difluorocarbene generated from difluoromethylene phosphobetaine (Ph3P+CF2CO2−) by decarboxylation
描述了一种由苄基溴合成宝石-二氟苯乙烯的新方法。的三苯基膦与苄基溴,得到鏻盐,相应的鏻盐,以产生磷叶立德,并与二氟卡宾从二氟亚甲基磷酸酯生成鏻内鎓盐的后续烯的脱质子化(PH季铵化3 P + CF 2 CO 2 -可以发生通过脱羧)在一个锅中平稳地进行,以高收率提供最终的宝石-二氟苯乙烯。
Stereospecific Synthesis of α‐Hydroxy‐Cyclopropylboronates from Allylic Epoxides
Herein, we report a catalytic and stereospecific method for the preparation of enantioenriched α‐hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively
Highly Efficient Fluorine-Promoted Intramolecular Condensation of Benzo[<i>c</i>]phenanthrene: A New Prospective on Direct Fullerene Synthesis
作者:Konstantin Yu. Amsharov、Mikhail A. Kabdulov、Martin Jansen
DOI:10.1002/ejoc.200900976
日期:2009.12
intramolecular condensation of benzo[c]phenanthrene under flash vacuum pyrolysis conditions. Methyl and fluorine functionalization were found to be promising approaches. Unexpectedly high selectivity was observed in the cyclization of fluorinated benzo[c]phenanthrenes. The mechanism for the condensation reaction and the advantages of fluorine as a promoter for the rational synthesis of fullerenes are discussed
Phosphonium Ylide-Mediated Programmable Fluorination to Access Mono- and Difluoromethylarenes
作者:Yu Zheng、Zhen-Zhen Xie、Xian-Chen He、Yan-Shan Chen、Wen-Shuo Cheng、Kai Chen、Hao-Yue Xiang、Xiao-Qing Chen、Hua Yang
DOI:10.1021/acs.orglett.1c00457
日期:2021.4.2
Compounds bearing fluorinated moieties are pervasive in a wide range of pharmaceuticals and agrochemicals. The installation of fluorinated units is a persistently vital task in synthetic chemistry, where facile and manipulable assays are highly demanding. Herein, we establish a general and programmable fluorination strategy for the modular assembly of mono- and difluoromethylarenes through the controllable