利用N-亞柳胺基酸衍生之掌性氧釩錯合物對β-硝基醇之衍生物進行光學對拆離之研究

Abstract

本論文主要是利用實驗室所發展的一系列N-亞柳胺基酸衍生之掌性氧釩錯合物，可以有效催化消旋化的β-硝基醇進行脫水及逆反應之光學對拆離。一開始的主軸是放在尋找最佳的反應條件，以及嘗試著更換受質的取代基，此外藉由在錯合物上亞柳基的苯環C-3及C-5位置植入不同取代基，成功的區分出β-硝基醇衍生物的鏡像異構物。當錯合物C-3位置植入1-萘基及C-5 位置植入硝基時，可得到43% 產率及73% 鏡像超越值的β-硝基醇，選擇性因子達12，同時也是第一個利用氧釩錯合物對β-硝基醇進行光學對拆離，且得到具有光學活性的β-硝基醇衍生物。The main purpose of this thesis is to show that a series of chiral vanadyl carboxylates derived from N-salicylidene-L-α-amino acids can be utilized to efficiently catalyze kinetic resolution of β-nitro alcohols with concomitant dehydration and retro-nitroaldol reaction. At first, we sought for the optimal conditions for the reaction with varying substitutions at the salicylidene template or the substrates. It was found that by changing the substituents at C-3 or C-5 positions of the N-salicylidene template, the racemic β-nitro alcohol was successfully resolved; When the substituent is 1-naphthyl at C-3 position and nitro group at C-5 position, resolved β-nitro alcohol was isolated in 43% yield and 73% ee (krel = 12). Furthermore, this study constitutes the first example of using chiral vanadyl complexes to catalyze efficient kinetic resolution of β-nitro alcohols.