Chelation-assisted transformation: synthesis of 1,4-dicarboxylate esters by the Rh-catalyzed carbonylation of internal alkynes with pyridin-2-ylmethanol.
The reaction of internal alkynes 1 with CO and pyridin-2-ylmethanol (2) in the presence of Rh(4)(CO)(12) results in a double-hydroesterification leading to 1,4-dicarboxylate esters 3. The reaction does not proceed via two consecutive hydroesterifications of alkynes, but the intermediacy of ketene intermediates is proposed. The coordination of the pyridine nitrogen in 2 to rhodium is essential for the reaction to proceed. [reaction: see text]
Inoue
Satoshi
S
Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
Yokota
Kazuhiko
K
Tatamidani
Hiroto
H
Fukumoto
Yoshiya
Y
Chatani
Naoto
N