The palladium-catalyzedcyclopropanation of strainedalkenes with 3-pinacolatoboryl-1-arylallyl carboxylates was explored. The reactions proceeded smoothly under mild conditions, and the cyclopropanation products were obtained in good to high yields with high diastereoselectivities if CsF, 18-crown-6, and molecular sieves were used as additives. The reaction was hypothesized to proceed through the
Reactivity of the alkene component in the ruthenium-catalyzed [2+2] cycloaddition between an alkene and an alkyne: Part 2
作者:Robert W Jordan、William Tam
DOI:10.1016/s0040-4039(02)01191-7
日期:2002.8
Ruthenium-catalyzed [2+2] cycloadditions of 2,3-disubstituted norbornadienes and 2-substituted norbornadienes with an alkyne were found to be highly chemo- and stereoselective with moderate level of regioselectivities and only small rate differences were observed with different substituents on the norbornadiene. (C) 2002 Elsevier Science Ltd. All rights reserved.