一.樟腦衍生物之對掌螯合劑在鏡像炔化加成反應之探討 二.樟腦衍生物之對掌輔助劑在非鏡像氮丙啶上的探討

Date
2007
Authors
潘麗雪
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Abstract
本論文主要分成兩大部分,摘要如下: 第一部分在探討以樟腦架構雙聚衍生物(114)作為不對稱炔化加成的對掌螯合劑。以苯甲醛為起始物,二乙基鋅為路易士酸進行炔化加成,可以得到R-form的炔丙基醇產物,其產率和鏡像超越值為90%和33%;當化合物114和四異丙醇化鈦在1:4莫耳數比例條件下,作為炔化加成之對掌催化劑,2-naphthaldehyde為起始物可得到50%的產率和86% ee的S-form產物,並利用反應機構解釋立體化學中心反轉之現象。 第二部份在探討以對掌α,β-不飽和醯胺進行不對稱氮丙啶反應。以N-Tosylcamphorpyrazolidinone為對掌輔助劑,製備α,β-不飽和醯胺衍生物,並以其為起始物,利用N-aminophthalimide和四醋酸鉛進行不對稱氮丙啶反應,可得到22-53%的產率和不錯的非鏡像選擇性(>95:5),產物之絕對立體組態經由X-ray單晶繞射確認。
The dissertation is divided into two section, they are as follows: I. The catalytic asymmetric alkyne addition to carbonyl compounds has attracted intense research activity in recent years because optically active propargylic alcohols are versatile precursors for synthesis of many chiral organic compounds. We have investigated the asymmetric alkynylzinc addition catalyzed by camphor derived 114 and Ti(Oi-Pr)4 and found that this catalyst system is moderate yield (50-95%) and enatioselectivity (19-86% ee). The absolute configuration of the newly generated stereogenic center in the product was determined to have an S-configuration. II. Aziridine is three-membered nitrogen-containing heterocycle of great importance as versatile chiral building block in organic synthesis. A new camphor-base chiral auxiliary N-tosylcamphorpyrazolidinone was synthesized, and test as a stereocontrolling element in aziridine reaction across a range of substrates. Treatment of N-tosylcamphorpyrazolidinone derived N-enones with N-aminophthalimide and lead tatracetate gave high diastereoselectivity (>95:5). The absolute configuration of the newly generated stereogenic center in product 297 was determined to have an R-configuration, as deduced from a single X-ray crystal analysis.
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氮丙啶, 炔化加成
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