Title

由丙炔醇或末端炔組成的含氧芳香烯炔化合物與釕錯合物催化之環化和環異構化反應

Translated Titles

Cyclization and Cycloisomerization Reactions of O-Containing Aromatic Enynes Consisting of Propargyl Alcohol or Simple Terminal Alkyne Catalyzed by Ruthenium Complexes

DOI

10.6342/NTU.2014.01429

Authors

賴盈瑄

Key Words

釕金屬 ; 丙炔醇 ; 烯炔 ; 催化 ; 苯並吡喃 ; 苯並呋喃 ; 苯並噁庚因 ; 環化反應 ; 環異構化反應 ; ruthenium ; propargylic alcohol ; enyne ; catalysis ; benzochromene ; benzofuran ; benzoxepine ; cyclization ; cycloisomerization

PublicationName

臺灣大學化學研究所學位論文

Volume or Term/Year and Month of Publication

2014年

Academic Degree Category

碩士

Advisor

林英智

Content Language

英文

Chinese Abstract

本篇論文探討藉由釕金屬錯合物誘發含氧原子芳香烯炔化合物進行分子內環化反應而形成含氧雜環產物。利用釕金屬錯合物[Ru]Cl([Ru]=Cp(PPh3)2Ru)與含有兩個甲基修飾在末端烯基之芳香炔丙醇1和7a在二氯甲烷溶劑下反應,可得到含氧六環的釕金屬亞乙烯基錯合物2和含氧五環的釕金屬亞乙烯基錯合物8與其他副產物。相同反應在甲醇為溶劑下,1則會進行連續環化反應得到含六氢-苯并[c]苯並吡喃結構之有機物5a和釕金屬碳烯錯合物4。同樣反應在甲醇為溶劑下,7a則會反應成四氢苯並[b,d]苯並呋喃結構之有機物12a,但是並不會產生相對應的釕金屬碳烯錯合物。我們推測要形成六氢-苯並[c]苯并吡喃和四氢苯並[b,d]苯並呋喃結構,是經由丙炔醇與烯基官能基作用,透過形成釕金屬亞丙烯型式的中間體,形成一次環化反應的釕金屬亞乙烯錯合物,之後再利用釕金屬α碳與乙烯基末端的碳原子作用進行二次環化反應。 不同於1和7a的反應,沒有甲基修飾在末端烯基之1,7-烯炔化合物7b在氯仿和甲醇混和溶劑下經由釕金屬錯合物[Ru]NCCH3+催化,則會進行涉及骨架重排的烯炔環異構化反應,產生有甲氧基加成之有機物15a。環異構化反應的進行是透過烯炔先與釕金屬進行雙牙配位,再氧化加成進行環金屬化反應形成金屬環戊烯中間體,然後經由涉及碳氧鍵和釕碳鍵斷裂與α碳β碳雙鍵生成之β氧脫去反應產生兩性離子的中間態,然後再重排結構與甲氧基加成形成15a。 利用釕金屬錯合物[Ru]Cl與含乙烯氧基在鄰位之芳香炔22a,在六氟磷酸鉀 存在下,於混合溶劑二氯甲烷與醇類(甲醇、乙醇和丙醇)中反應16小時,相對應產生含烷氧基加成之苯並噁庚因結構的黃色油狀有機物23a-c,此反應透過形成釕金屬亞乙烯基錯合物,再進行釕金屬亞乙烯基錯合物之α碳β碳雙鍵與乙烯氧基的[2+2]環加成反應形成碳烯錯合物,之後烷氧基加成導致C-C腱斷裂而形成產物。此外如果改變乙烯氧基上的取代基位置像是23b,則也可以產生相對應的噁庚因錯合物。若是改成在二氯甲烷非親核性溶劑下,則會進行環異構化反應形成碳烯錯合物24,此反應進行涉及到形成釕金屬亞乙烯基錯合物,再進行釕金屬亞乙烯基錯合物之釕金屬α碳雙鍵與乙烯氧基的[2+2]環加成反應,然後再骨架重排形成24。

English Abstract

The intramolecular cyclization of aromatic enyne containing oxygen-atom mediated by ruthenium complex, leading to the formation of the oxygen heterocycle is described. Ruthenium complex [Cp(PPh3)2Ru]Cl assisted cyclization of two propargylic alcohols 1 and 7a each containing two terminal methyl groups on the olefinic parts yielded the vinylidene complexes 2 and 8 with a new six-membered and five-membered ring, respectively, in CH2Cl2 among other products. In MeOH, tandem cyclization of 1 yielded the organic compound 5a and the carbene complex 4 with a 6H-benzo[c]chromene moiety. Similarly, 12a with a tetrahydrodibenzo[b,d]furan moiety was obtained from 7a; however, with no comparable carbene complex. The unit reactions yielding these 6H-benzo[c]chromene and tetrahydrodibenzo[b,d]furan species may proceed via a first cyclization reaction between propargylic alcohol and alkenes through the allenylidene intermediate giving vinylidene species followed by second cyclization between Cα and the terminal carbon of the vinyl group. Unlike the reactions of 1 and 7a, the 1,7-enyne 7b containing no methyl group on the olefinic part underwent enyne cycloisomerization involving skeletal rearrangement when catalyzed by [Ru]NCCH3+ in a co-solvent of CHCl3 and MeOH to yield the product 15a with an addition of methoxy group. The cycloisomerization reaction proceeds via a bidentate coordination of enyne to ruthenium metal and then the reaction is followed by an oxidative cyclometalation to give metallacyclopentene involving a β-oxygen elimination via disruption of both C-O bond and Ru-Cα bond to form a double bond between Cα and Cβ to generate the zwitterionic intermediate. And then, the reaction proceeded to undergo rearrangement and addition of methoxy group to produce 24. Treatment of ethynylbenzene 22a containing a vinyloxy group at the ortho position of the aryl ring with a catalytic amount of [Ru]Cl in the presence of KPF6 in a co-solvent of CH2Cl2/ROH (R = Me, Et, i-Pr) for 16 h afforded yellow oil 23a-c containing benzoxepine with addition of an alkoxy group. The formation of 23a is via generation of vinylidene complex and subsequent [2+2] cycloaddition of vinylidene Cα=Cβ bond with the olefin on vinyloxy group to give bicyclic carbene complex followed by addition of an alkoxy group to disrupt the C-C bond. In addition, changing the substituent on the vinyl group, such as that in 22b, also produced the corresponding benzoxepine derivatives. In CH2Cl2, cycloisomerization of 22a gave the carbene complex 24. The reaction involved generation of a vinylidene complex followed by a subsequent [2+2] cycloaddition of vinylidene Ru= Cα bond with an olefin on vinyloxy group. And then, the reaction proceeded to undergo skeletal rearrangement to produce 24.

Topic Category 基礎與應用科學 > 化學
理學院 > 化學研究所
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