syntheses. However, the synthesis of acid–base catalysts is problematic due to the neutralization of acidic and basic groups. This work reports a facial approach to solve this problem via the synthesis of a novel bifunctional polymer using inexpensive materials and easy methods. In this way, at the first step, heterogeneous poly (styrene sulfonic acid‐n‐vinylimidazole) containing pentaerythritol tetr
Nitrile biotransformations for the practical synthesis of highly enantiopure azido carboxylic acids and amides, ‘click’ to functionalized chiral triazoles and chiral β-amino acids
作者:Da-You Ma、De-Xian Wang、Qi-Yu Zheng、Mei-Xiang Wang
DOI:10.1016/j.tetasy.2006.08.021
日期:2006.9
(R)-12a underwent ‘click’ reactions with diethyl acetylenedicarboxylate and phenylacetylene to produce functionalized chiral triazoles 14 and 15, respectively. The easy preparation of the starting nitrile substrates, highlyefficient and enantioselective biotransformation reactions, and versatile utility of the resulting functionalized azido carboxylic acids and amidederivatives, render this method very
The cobalt-catalyzed reduction of unsaturated α-cyano carboxylic esters using sodium borohydride (NaBH4) leads to the corresponding saturated cyano alcohols in high yields. In particular, the new catalytic system cobalt(II) chloride-diisopropylamine in combination with NaBH4 showed excellent activity in the chemoselective reduction of a variety of carboxylic esters to their corresponding alcohols in