Carboxylate-Directed Kumada Coupling of an Acetaldehyde Synthon with 2-Bromobenzoates Used towards the Synthesis of Isochromanes
作者:Ioannis Houpis、Jean-Pierre Van Hoeck、Ulf Tilstam
DOI:10.1055/s-2007-985572
日期:——
This letter describes the Kumada coupling of bromobenzoic acid derivatives with the acetaldehyde enolate synthon (1,3-dioxolan-2-ylmethyl)magnesium bromide. The lithium carboxylate salt shows the highest reactivity in the coupling reaction while addition of t-BuOLi affords optimal selectivity. During this work, we have observed a strong directing effect of the sodium carboxylate function which can be useful in differentiating electronically similar diaryl bromides.