Solvent-free Zn(OTf)<sub>2</sub>-catalyzed dehydrative cross coupling of propargyl alcohols with diarylphosphine oxides to afford allenylphosphine oxides
Abstract A less expensive and more environmentally friendly Zn(OTf)2-catalyzed dehydrative coupling reaction of propargyl alcohols with diarylphosphine oxides is reported. The reaction takes place under mild and solvent free conditions, and features a high regioselectivity to provide an effective method for the synthesis of some diarylphosphinyl allenes in moderate to high yields. Graphical Abstract
Cadmium(II) Chloride-Catalyzed Dehydrative C−P Coupling of Propargyl Alcohols with Diarylphosphine Oxides to Afford Allenylphosphine Oxides
作者:Jianlin Yang、Ming Zhang、Kang Qiu、Lize Wang、Jingjing Yu、Zefeng Xia、Ruwei Shen、Li-Biao Han
DOI:10.1002/adsc.201700957
日期:2017.12.19
The reaction can also be easily scaled up to a gram‐scale synthesis. A mechanism study indicates that the reaction may proceed through a process of propargylic substitution to generate phosphonite intermediates followed by [2,3] sigmatropic rearrangement to produce the allenyl products, rather than through a common allenylative substitution resulting from P‐nucleophilicity.
Studies on highly regio- and stereoselective fluorohydroxylation reaction of 3-aryl-1,2-allenyl phosphine oxides with Selectfluor
作者:Guangke He、Chunling Fu、Shengming Ma
DOI:10.1016/j.tet.2009.07.009
日期:2009.9
The fluorohydroxylation of allenyl phosphine oxides with Selectfluor in commercial MeCN without prior treatment or a mixed solvent of anhydrous MeCN (refluxed over CaH2 and distilled before use) and 7.0 equiv of H2O or MeNO2/H2O=10/1 afforded 2-fluoro-3-hydroxy-1(E)-alkenyl diphenyl phosphine oxides in moderate yields with very high regio- and stereoselectivities. The E-stereoselectivity is believed to be controlled by the phosphine oxide functionality. In the reaction of 3-(4-methoxyphenyl)-1,2-propadienyl diphenyl phosphine oxide, further fluorination on the electron-rich phenyl ring was also observed. (C) 2009 Elsevier Ltd. All rights reserved.