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Updated: Jun 6, 2026

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)
Published on: November 22, 2016
Synthesis of 2-perfluoroalkyl 4H- and 2H-chromenylphosphonates mediated by amines and phosphines
Blazej Duda1, Sergey N Tverdomed, Gerd-Volker Röschenthaler
1School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
Abstract:
An efficient synthesis of 2-perfluoroalkyl 4H-chromen-3-ylphosphonates 4a-i (R(F) = CF(3)) and 5a-i (R(F) = C(2)F(5)) has been accomplished via regioselective cycloaddition of 2-hydroxybenzaldehydes to diethyl 3,3,3-trifluoropropyn-1-yl- and diethyl 3,3,4,4,4-pentafluorobutyn-1-ylphosphonate, using trialkyl amines or phosphines as mediators. 2H-Chromen-3-ylphosphonates 6a-i were regioselectively obtained in the presence of triphenylphosphine. A convenient method for the isomerization of 4H-chromen-3-ylphosphonates into 2H-chromen-3-ylphosphonates 6a-i (R(F) = CF(3)) and 7a-i (R(F) = C(2)F(5)) was established.
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