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Indium을 이용한 수용액 상에서의 반응 연구

Title
Indium을 이용한 수용액 상에서의 반응 연구
Authors
강소연
Issue Date
2001
Department/Major
대학원 화학과
Publisher
이화여자대학교 대학원
Degree
Master
Abstract
대부분의 indium 반응이 activated halide와의 반응으로 한정되어있으며, activated halide의 경우에도 Barbier-type allylation에서는 allylic chloride가 반응성이 떨어지는 것으로 보고 되었으나, sonication 혹은 palladium을 catalyst(acetate, alcohol인 경우도 가능)로 하여 가능한 것으로 알려졌다. 이를 Barbier-type reaction에 이용하여 bifunctionalized allylic compounds와 dicarboxabenzaldehydes를 반응시켜 macrocyclized compounds를 얻고자 하였다. 또한 In / InCl₃를 이용하여 methyl vinyl ketone과 aldehydes의 cross-coupling을 성공적으로 수행하였다. A. Indium의 Barbier-type reaction을 이용한 cyclization에 관한 연구 . Indium에 대한 다양한 결과들이 발표되면서, 주로 Barbier-type reaction 혹은 Reformatsky-type reaction에 많은 응용의 결과가 있었다. 본 실험에서는 Barbier-type allylation을 이용, dicarboxabenzaldehyde에 allyl dihalide를 반응시켜 얻어진 다양한 화합물을 분리, 밝히고자 하였다. B. Indium과 Indium(III)chloride를 이용한 benzaldehyde와 methyl vinyl ketone의 Cross-Coupling 반응. (β,γ-unsaturated ketones의 새로운 합성 방법 개발) β,γ-unsaturated ketones은 drug이나 agrochemical의 합성 중간체로써 유용하다고 알려져 있으며^5, 그것의 합성방법^6이 olefin acylation, 전이금속을 이용한 합성, Claisen rearrangements, direct oxidation, allylic organometallic의 반응 등 다양함에도 불구하고, α,β-unsaturated ketone이 side반응으로 수반되는 문제점을 가지거나, 반응 자체에 제한, 또는 복잡한 반응 과정 때문에 유용한 합성 방법은 몇몇에 불과하다.^7,^8 Indium을 이용한 C-C bond forming reaction 을 연구하던 중, indium에 additives로 InCl₃를 첨가하여 cinnamaldehyde가 coupling이 일어나는 것에 착안, aromatic aldehyde와 α,β-unsaturated carbonyl compounds인 acrolein의 반응에서 unknown mixture의 생성이 확인되었다. 즉, 이를 통해 두 반응물 사이에 반응성이 있음을 알고, aldehyde인 acrolein대신 ketone인 MVK를 반응시켜 coupling된 β,γ-unsaturated Ketone을 44-79%의 수율로 얻을 수 있었다.;Among versatile metal-mediated organic reactions, particularly indium is of current attraction due to its meditation ability for many organic transformations in aqueous media. The lower level of the first ionization potential of indium metal compared to that of Mg, Sn, or Zn and its exceptional stability in water makes this metal apply to many organic reactions. In view of the recent interest on the use of indium in organic conversions, we wished to study its meditation effect in the Michael reaction which is one of the most efficient methods for carbon-carbon bond formation and has broad applications in organic synthesis. Herein we report that indium-mediated reaction of benzaldehydes and methyl vinyl ketone proceeded smoothly in the presence of InCl₃ in aqueous media to form β,γ-unsaturated ketone. Thus reactions of benzaldehydes and 3 equimolar amounts of MVK with indium powder(-100 mesh, 300 M%) and InCl₃(200 M%) in a 1:2 mixture of THF and H₂O at room temperature for 6 hrs formed the β,γ-unsaturated ketones in respectable yields. Methyl vinyl ketone was used in excess due to the susceptibility of MVK to dimerization. This reaction provides a very effective access to β,γ-unsaturated ketones which are known to be useful intermediates in the synthesis of finechemicals. No reaction was occurred in the absense of In or InCl₃. Using other Lewis acids such as SnCl₄, FeCl₃ and CuCl₂ instead of InCl₃ resulted in low yields(21-38%) of the corresponding products. These reaction conditions were extended to other Michael acceptors like acrolein, acrylonitrile, ethyl acrylate and acrylic acid without success. The reaction mechanism still remains. Particularly, it was noted that reaction using 2.5 equimolar amounts of indium(I) chloride alone without indium metal also proceeded well to give the b,γ-unsaturated ketone in 78% yield. Another investigation of indium-mediated reaction was the Barbier-type allylation which is the most widespread application in organic synthesis. We previously reported that various allylating reagents can be effectively applied to palladium-catalyzed allylation of carbonyl compounds with In-InCl₃ system in aqueous media. So, we report the cyclization from bifunctional allylic compounds and isophthalic or phthalic dicarboxaldehydes.
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