1.
J Org Chem
; 75(21): 7475-8, 2010 Nov 05.
Article
in English
| MEDLINE
| ID: mdl-20929205
ABSTRACT
The low-temperature Evans-Tishchenko coupling of a range of functionalized heteroaryl aldehydes with ß-hydroxy ketones in the presence of a Sm(III) catalyst has been achieved with high yields (90-99%) and good to excellent diastereoselectivity (90:10 â 95:5 dr). However, at room temperature a retro-aldol aldol-Tishchenko reaction was found to compete with the desired Evans-Tishchenko reaction. Identification of these byproducts has allowed the corresponding aldol-Tishchenko reaction to be optimized for several heteroaryl aldehydes.