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  • 學位論文

釕金屬錯合物誘發含末端炔氮丙啶化合物之擴環反應的研究

Study on ring-expansion reaction of terminal-alkyne-containing aziridine compounds induced by ruthenium metal complexes

指導教授 : 劉陵崗
共同指導教授 : 林英智(Ying-Chih Lin)

摘要


本論文中,我們探討含末端炔氮丙啶化合物與半三明治狀含磷釕金屬環戊二烯錯合物之反應。藉由釕金屬錯合物之誘發,含末端炔氮丙啶化合物進行擴環反應以生成五環或六環之產物。我們合成二種型態之氮丙啶化合物,化合物2a-c與3d-e含丙炔醇官能基,其中化合物3d-e建構於環狀烷上;化合物4f-h則含末端炔取代氮丙啶基團。藉由金屬誘發擴環反應,我們得到多樣之最終產物,其反應路徑經由5-endo-dig之環化加成或金屬亞乙烯基中間產物。此外,發生於四級胺陽離子之多樣化擴環反應伴隨稀有之骨架重排。金屬起始物[Cp(PPh3)2Ru]Cl (1)及[Cp(dppe)Ru]Cl (1’)與化合物2a-c在六氟磷酸鉀之存在下,於甲醇中反應生成含氮六環取代之釕金屬錯合物陽離子。其反應經由在π-配位中間產物發生之5-endo-dig環化加成,進而擴環亦伴隨新穎之重排反應。根據化合物2a-c於氮丙啶之不同取代基,我們得到不同的最終產物。金屬起始物1及1'與化合物2c (R1 = R2 = H)之反應中,我們分別得到吡啶間位取代之釕金屬錯合物6c及6c'。然而,化合物2a (R1 = R2 = Me)之反應生成含甲醇加成之錯合物5a。於單一甲基取代之化合物2b的反應中,我們同時得到二種型態之產物5b與6b。其中錯合物5b於攝氏60度藉由脫去甲醇轉化成錯合物6b。佐以重氫與碳-13同位素標記之研究,我們得以推測以上反應之機制。 此外,我們亦探討含環狀烷之氮丙啶取代丙炔醇化合物之反應。於化合物3d中,其末端炔與氮丙啶分別位於環己烷之二個位向,與金屬起始物1’在六氟磷酸鉀之存在下,於甲醇中反應生成環狀氮取代金屬碳烯錯合物7d'與8d’,而二者皆具有反式-[4,3,0]-雙環骨架。其中含二甲基縮酮之錯合物7d'為主要產物,而其對應之酮官能基異構物8d’則為次要產物。基於空間限制,化合物3d藉由π-配位之環化加成並不被允許。取而代之地,其反應經由釕金屬亞乙烯基錯合物與釕金屬亞丙二烯基錯合物之轉換,進而伴隨類嚬哪醇重排或環丙基之生成與開環步驟。 藉由金屬錯合物1之催化,含芳香環之末端炔取代氮丙啶化合物4g與4h轉化形成對應之2-取代吡咯。其催化循環經由釕金屬亞乙烯基中間產物之形成,進而發生氮丙啶之擴環反應,以及後續質子位移與質子誘發脫去金屬之步驟。藉由含烷基之末端炔取代氮丙啶化合物4f之計量反應,我們得到環狀氮取代金屬碳烯中間產物9f。

並列摘要


Reactions of alkynyl aziridine compounds with half-sandwiched ruthenium Cp phosphine complexes are explored. Ring-expansion reaction of these alkynyl aziridines is induced by ruthenium metal complexes to form either five- or six-membered ring products. Two types of aziridinyl compounds 2a-c and 3d-e containing propargylic alcohol moieties with and without cycloalkane and the other aziridinyl compounds 4f-h containing alkynyl groups are prepared. Different final products were obtained from metal induced ring expansion and the transformation proceeds through either a 5-endo-dig cycloaddition or via formation of metal vinylidene intermediate. Also, various ring expansion processes on the quarternary ammonium cation are accompanied with rare skeletal rearrangements. Reactions of [Cp(PPh3)2Ru]Cl (1) and [Cp(dppe)Ru]Cl (1’) with 2a-c in the presence of KPF6 in MeOH afford the cationic ruthenium N-heterocyclic complexes with six-membered ring skeleton. The transformation proceeds through a 5-endo-dig cycloaddition via π-coordinated species and the ring expansion is accompanied with a new rearrangement. Depending on the substituents on the aziridinyl ring, different final products were obtained from 2a-c. The ruthenium 3-(N-benzyl)pyridinyl complexes 6c and 6c’ are formed from the reactions of 2c (R1 = R2 = H) with 1 and 1’, respectively. However, the reaction of 2a (R1 = R2 = Me) leads to complex 5a including a MeOH addition. In the reaction of 2b with only one methyl substituent, two kinds of products 5b and 6b are simultaneously obtained. Complex 5b transforms into complex 6b by a MeOH elimination at 60 ºC. The mechanism was proposed based on both D- and 13C-isotopic labeling studies. The second type of aziridinyl propargylic alcohols involves cycloalkane ring. Treating the propargylic alcohol 3d in which the terminal alkyne and aziridine are anti- to each other on a cyclohexyl ring, with 1’ in the presence of KPF6 in MeOH yields the cationic cyclic aminocarbene complex 7d’ bearing a dimethyl ketal on the trans-[4,3,0]-bicycle skeleton as the major product, and the corresponding ketone isomer 8d’ as the minor one. Because of the spatial limitation, the cycloaddition of 3d through π-coordination is forbidden. The transformation proceeds via the alternative route on a basis of ruthenium vinylidene and allenylidene interchange followed by a semipinacol rearrangement or a cyclopropyl ring formation-opening process. Transformations of aryl-substituted alkynyl aziridines 4g and 4h into the corresponding 2-substituted pyrroles are catalyzed by 1. The catalytic cycle proceeds through formation of the ruthenium vinylidene intermediate, followed by a ring-expansion of the aziridinyl ring and subsequent proton-shift/proton induced-demetallation steps. The intermediate cyclic aminocarbene complex 9f was isolated from the stoichiometric reaction of alkyl-substituted alkynyl aziridine 4f.

參考文獻


[82] Sugiyama, S.; Fukuchi, H.; Ishii, K. Tetrahedron 2007, 63, 12047-12057.
[79] Wang, Y.-C.; Lin, Y.-C.; Liu, Y.-H. Chem. Asian J. 2012, 7, 2703-2710.
[1] Sweeney, J. B. Chem. Soc. Rev. 2002, 31, 247-258.
[3] Tanner, D. Angew. Chem. Int. Ed. 1994, 33, 599-619.
[4] Yudin, A. K. In Aziridines and Epoxides in Organic Synthesis; Wiley-VCH: Weinheim, 2006.

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