一、樟腦衍生之對掌輔助劑在非鏡像環氧化之探討 二、新有機催化劑之開發研究

楊舜雯(Shuen-Wen Yang)

指導教授 ： 陳焜銘

國立臺灣師範大學/理學院/化學系/碩士(2006年)

摘要

本論文主要分為兩個部分，摘要如下：
第一部分旨在研究以樟腦架構為主的對掌輔助劑N-tosylcamphorpyrazolidinone在有機不對稱合成上的應用，探討此對掌輔助劑衍生之α,β-不飽和醯胺為共軛受質，進行不對稱環氧化反應。N-tosylcamphorpyra
zolidinone衍生之N-methacryloyl tosylcamphorpyrazolidinone與N-tigloyl tosylcamphorpyrazolidinone，分別以UHP/TFSA及methyl(trifluoromethyl)dioxirane為氧化劑時，可得到高立體組態反轉之非鏡像環氧異構物。以UHP/TFSA為氧化劑時，起始物之分子以s-cis構型為主，利於分子間氫鍵作用，以N-tigloyl tosylcamphorpyrazolidinone為受質可得到相當高之非鏡像超越值，經由1H-NMR分析其相關訊號，非鏡像選擇性大於95% de，其主要產物之絕對立體化學由X-ray單晶繞射確定為(1R,2S)，產率為60%。以methyl(trifluoromethyl)dioxirane為氧化劑時，受到電子斥力與立體障礙影響，起始物之分子以s-trans構型為主，以N-methacryloyl tosylcamphorpyrazolidinone為受質可得到非鏡像超越值90% de，其主要產物之絕對立體化學由X-ray單晶繞射確定為(1S)，產率為90%。因此，藉由不同的環氧化試劑，造成雙鍵可以不同面向進行環氧化加成反應，得到高立體選擇性反轉之產物。
第二部分是新有機催化劑之開發研究。利用順-丁烯二酸（maleic acid）與phenyl hydrazine合成新有機催化劑5-oxo-1-phenyl-pyrazolidine-3-carboxylic acid，再與樟腦架構為主的對掌輔助劑camphor pyrazolidinone進行醯胺化反應，製備新有機催化劑148與150，並將其應用於不對稱合成反應上，期能達到催化各種不對稱反應並提高產物之立體選擇性。

關鍵字

不對稱 ； 環氧化 ； 有機催化 ； 樟腦

並列摘要

The dissertation is divided into two parts:
Camphor derived ?,?-unsaturate N-tosylcamphorpyrazolidinone were prepared and subject to asymmetric epoxidation. N-Tosylcamphorpyrazolidinone derived N- methacryloyl tosylcamphorpyrazolidinone and N-trigloyl tosylcamphorpyrazolidinone were treated with UHP/TFSA and methyl(trifluoromethyl)dioxirane, respectively to afford excellent material yield and with opposite diastereoselectivies. When the reaction was treated with UHP/TFSA, s-cis conformation of camphor derived ?,?- unsaturate substrates is favored due to the beneficial intermolecular hydrogen bonding. To regard N-trigloyl tosylcamphorpyrazolidinone as substrate, the major product was isolated in good yield (60%). The diastereoselectivity was determined to be >95% by 1H-NMR analysis. The absolute stereochemistry of the newly generated chiral center was determined to be a (1R, 2S)-configuration by single crystal X-ray analysis. When the reaction was treated with methyl(trifluoromethyl)-dioxirane, s-trans conformation is favored due to repulsion of electron and stereohindrance of the sulfonyl group. To regard N-Methacryloyl tosylcamphorpyrazolidinone as substrate, the major product was isolated in good yield (90%) and good to excellent diastereoselective was obtained(90% de). The absolute stereochemistry of the major product was determined to be a (1S)-configuration by single crystal X-ray analysis. Therefore, the different facial of alkene were attacked by changing different oxidants to obtain excellent but opposite diastereoselective product.
The second part of this dissertation present the design and synthesis of new organo- catalyst. New organocatalyst 5-oxo-1- phenyl-pyrazolidine-3-carboxylic acid was pre- pared from maleic acid and phenyl hydrazine, which was treated with camphor derived camphorpyrazolidinone to provide new organocatalyst (148 and 150) via amide bond formation. Preliminary studies were carried out using the new organocatalyst to catalyze asymmetric synthesis. We hope the new organocatalyst (148 and 150) can be applied to asymmetric synthesis and afford excellent stereoselective.

並列關鍵字

Camphor ； asymmetric epoxidation ； organo- catalyst

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