Tetrahedron

Versatile synthesis of (Z)-1-alkylidene-1, 3-dihydroisobenzofurans and 1H-isochromenes by palladium-catalyzed cycloisomerization of 2-alkynylbenzyl alcohols

B Gabriele, G Salerno, A Fazio, R Pittelli

Index: Gabriele, Bartolo; Salerno, Giuseppe; Fazio, Alessia; Pittelli, Rosina Tetrahedron, 2003 , vol. 59, # 33 p. 6251 - 6259

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Citation Number: 103

Abstract

An easy synthesis of (Z)-1-alkylidene-1, 3-dihydroisobenzofurans and 1H-isochromenes by palladium-catalyzed cycloisomerization of readily available 2-alkynylbenzyl alcohols under neutral conditions is reported. Reactions were carried out at 70–100° C in the presence of catalytic amounts (1–2%) of PdI2 in conjunction with 2equiv. of KI for 1.5–24 h. The preference towards the 5-exo-dig cyclization mode (leading to 1, 3-dihydroisobenzofurans ...