可回收水溶性鈀觸媒催化Hiyama與末端炔自身偶合反應

Hiyama and Terminal Alkynes Homocoupling Reactions Catalyzed by a Reusable Cationic 2,2′-Bipyridyl/Palladium System in Water

陳劭農(Shao-Nung Chen)

指導教授 ： 蔡福裕

國立臺北科技大學/工程學院/有機高分子研究所/碩士(2009年)

摘要

本論文為使用過渡金屬作催化劑反應，我們以綠色化學的觀點希望能使用實驗室開發的水溶性配位基形成水溶性鈀觸媒，利用無毒無害且便宜的水來當反應溶劑，屏除傳統化學反應需在惰性氣體狀態下反應的觀點，在空氣中即可使反應進行，催化劑在反應結束後可以與產物簡單的分離進行回收再使用。
在Hiyama反應中我們不需要以往使用含氟添加物，在120℃下催化aryl bromides 與 organosilanes反應得到各種不同biaryl形式的產物，催化劑量可低至0.001 mol％。反應結束後經過萃取後水溶液經四次反應循環後仍保有高度的催化活性。末端炔自身偶合反應中可以在水溶性鈀觸媒1-0.0001 mol％、CuI 1 mol％ 催化下可有高度反應性來取得diynes產物，反應中可發現添加氧化劑I2時可將反應性大幅度提升，反應結束後的水溶液也可使反應再使用四次後產率依然有80％以上，最後發現反應在沒有使用水溶性鈀觸媒時反應結果會趨向末端炔碘化反應，將反應條件稍作調整後可得到一系列末端炔碘化的產物。

關鍵字

綠色化學 ； 水溶性觸媒 ； 鈀 ； Hiyama ； 末端炔 ； 自身偶合 ； 再使用

並列摘要

The palladium-catalyzed cross-coupling reactions for the synthesis of biaryls and buta-1,3-diynes is one of the most powerful methods in modern organic synthesis.To date, most reactions were carried out in organic solvents and under inert atmosphere. The use of water as a solvent is an environmentally friendly, inflammable, and inexpensive solvent,which is excellent from the viewpoint of green chemistry. There are several advantages when water replaces of the organic solvent as a reaction medium, such as easy product isolation, nonflammability, low toxicity, and protection of public health and the living environment.
The Hiyama reaction were carried out with low catalyst loading (0.01-1mol% Pd) to give the products under fluoride-free conditions and aerobic conditions in water. The convenient prepared catalyst showed slight loss of its activity in the recycling process of coupling of 4-bromoacetophenone and phenyltriethoxysilane after three times.
The homocoupling of terminal alkynes at room temperature using water as a solvent in the presence of TBAB under aerobic conditions. For aromatic terminal alkynes, the reaction was performed either with or without I2 as an oxidatant; the addition of I2 was required when aliphatic terminal alkynes was used as substrates for homocoupling reaction. In the presence of 0.0001–1 mol% palladium catalyst and 1 mol% CuI, a variety of terminal alkynes were coupled in good to excellent yields. The water-soluble catalytic system was separated from the organic products by extraction and the residual aqueous solution showed activity for reuse for several cycles.

並列關鍵字

green chemistry ； water-soluble catalyst ； palladium ； Hiyama ； terminal alkyne ； homocoupling ； reusable

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