reacts more slowly, producing mainly the α-selenenyl adduct. Dehydrohalogenation of adducts provides a general and valuable method for the preparation of olefins carrying methyl or phenylselenenyl groups in α-position to electron-withdrawingsubstituents.
Several capto-dative olefins containing the phenylselenenyl group have been obtained via selenenyl halide addition to acrylic derivatives followed by halide elimination. Some of the olefins efficiently trap the radicals formed from azobisisobutyronitrile (AIBN) and methyl azobisisobutyrate (MAIB) to form intermediate bridged dehydrodimers, which spontaneously lose diphenyldiselenide to produce new
Captodative substituent effects — Part XXXI olefins with captodative substitution in [2+2] cycloadditions
作者:Ch. De Cock、S. Piettre、F. Lahousse、Z. Janousek、R. Merényi、H.G. Viehe
DOI:10.1016/s0040-4020(01)97193-5
日期:1985.1
Olefins with captodative substitution are excellent partners in [2+2] cycloadditions leading to cyclobutane derivatives. The reaction rates increase with the radical stabilising power of the substituents. Thio- and selenoalkyl(aryl) substituted gemdifluoroolefins allow the synthesis of new cyclobutane derivatives.