Allylmetallation of 1-silylalkynes by 2-(bromozincmethyl)-2-alkenyl ethers followed by Pd(0)-catalyzed cyclization: A one-pot synthesis of 4-methylenecyclopentenes
作者:Jaap van der Louw、Juul L. van der Baan、Franciscus J.J. de Kanter、Friedrich Bickelhaupt、Gerhard W. Klumpp
DOI:10.1016/s0040-4020(01)89857-4
日期:1992.1
Reaction of 2-(bromozincmethyl)-2-alkenyl ethers 1a,b,c,d with 1-(trimethylsilyl)-1-alkynes 2 afforded carbometallation products 3, which were converted by Pd(0)-catalyzed cyclization to 4-methylenecyclopentenes 5. The rates of both the addition and cyclization step depend on the concentration of the organozinc compound and the preparation of 5 is best performed using a 1.4–1.8 M solution of 1. At