Allylmetallation of 1-silylalkynes by 2-(bromozincmethyl)-2-alkenyl ethers followed by Pd (0)-catalyzed cyclization: A one-pot synthesis of 4-methylenecyclopentenes
J van der Louw, JL van der Baan, FJJ de Kanter…
文献索引：Louw, Jaap van der; Baan, Juul L. van der; Kanter, Franciscus J. J. de; Bickelhaupt, Friedrich; Klumpp, Gerhard W. Tetrahedron, 1992 , vol. 48, # 29 p. 6087 - 6104
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 lower concentrations reaction times ...
