Cyclization and rearrangement products from coupling reactions between terminal o-alkynylphenols or o-ethynyl(hydroxymethyl)benzene and 6-halopurines
作者:Tom Christian Berg、Vebjørn Bakken、Lise-Lotte Gundersen、Dirk Petersen
DOI:10.1016/j.tet.2006.03.112
日期:2006.6
the (Z)-isomer. The latter compound was also formed from a two-step reaction; Sonogashira coupling with O-silylated alkyne followed by deprotection and subsequent 5-exo cyclization. Sonogashira coupling between 6-halopurines and 2-propynylphenol gave only the alkyne coupling product and no cyclization took place. However, the Sonogashira product was unexpectedly rearranged to 6-(3-phenoxypropa-1,2-dienyl)purines