Synthesis of (<i>Z</i>)-2-[(<i>Z</i>)-3-Alkylideneisobenzofuran-1(3<i>H</i>)-ylidene]acetic Acid Derivatives by Sequential Coupling-Cyclization between 3-(2-Iodophenyl)-3-oxopropanoic Acid Derivatives and Terminal Alkynes
3-(2-Iodophenyl)-3-oxopropanoic acid derivatives reacted efficiently with various terminal alkynes in the presence of catalytic amounts of dichlorobis(triphenylphosphine)palladium and copper(I) iodide and two molar amounts of triethylamine in N,N-dimethylformamide at room temperature to afford the corresponding (Z)-2-[(Z)-3-alkylideneisobenzofuran-1(3H)-ylidene]acetic acid derivatives in reasonable yields.
Palladium(0)-catalyzed 5- exo - dig O -cyclization/coupling of ethyl 3-(2-alkynylphenyl)-3-oxopropanoates with aryl iodides to 1,3-dihydroisobenzofurans
Palladium-catalyzed highly regioselective 5-exo-dig O-cyclization/coupling of a series of ethyl 3-(2-alkynylphenyl)-3-oxopropanoates with aryl iodides has been developed for the synthesis of (Z)-alkylidene-1,3-dihydroisobenzofuran derivatives. Reactions of ethyl 3-(2-alkynylphenyl)-3-oxopropanoates and aryl iodides are carried out in DMSO at 80 degrees C with 5 mol % Pd(PPh3)(4) and 2 equiv of Et3N as a base for 4 h in modest yields. (C) 2015 Elsevier Ltd. All rights reserved.