Cyclization of 1,6-diyne and 1,6-enyne with Aromatic Linkage Induced by Ruthenium Complex

我們研究含連結末端丙炔醇1,6烯炔化合物1N與釕金屬之三苯基磷化合物 Cp(PPh3)2RuCl的反應。如1N與釕金屬錯合物反應會產生高產率phosphornium乙炔基錯合物2。如果在Cgamma修飾兩種類型取代基，則會造成不同的環化反應趨勢。為了修飾不飽和烷基官能團在Cgamma位置，錯合物2用乙烯基和異丙烯基格林納試劑分別反應形成4a和4b。隨後去保護基反應得含末端三鍵氫5a和5b。Cbeta和末端炔基碳的環合反應是經由6-endo-dig途徑，生成含六元環之環合亞乙烯基。6a和6b的包括1H，31P，13C，COSY，HSQC，HMBC光譜特徵和質譜分析佐證。 錯合物2和K2CO3在醇類中反應，產生含烷氧基醇修飾的乙炔基錯合物7a和7b。7a和7b揭示了兩個不同碳-碳鍵生成的途徑。為了尋找控制的因素，我們進一步的設計不同環境的實驗，發現溶劑在異構物環化反應中的過程，扮演了重要角色。對於 10a和8a，我們假設非質子 - 質子溶劑的本質上的特性，支配6-endo-dig和5-exo-dig環化的途徑。此外，錯合物2在乙醇中，進行類似的反應，產生 8b和10b。然而，對於7b，經由5-exo-dig途徑，形成五元環產物10b之異構物選擇性較低。此外，在微鹼性的環境下，10a和10b可以經由碳炔的途徑，轉換形成含醯基的喹啉化合物。相反的，在氯仿條件下，8a可經由1,3甲烷氧基轉移，形成碳烯。 除了雙炔的研究，我們還用1,6-烯炔1，來研究乙炔基錯合物的反應性。將烯炔1與 Cp(PPh3)2RuCl在加入的KPF6的甲醇中反應，生成亞乙烯基錯合物12。將12在甲醇中加入NaOMe，進行去質子反應，形成乙炔基錯合物13。對於13，Cbeta與乙烯碳之間產生環化反應，形成一個環合亞乙基錯合物14。其結構是由1H，31P，13C，HMBC圖譜和質譜分析所鑑定。We studied the chemical reactions of Cp(PPh3)2RuCl with 1,6-endiyne compound 1N in which one of the triple bonds is propagylic alcohol. At first, reaction of 1N with ruthenium complex generates phosphonium acetylide complex 2 in high yield. Modification of different functional groups at Cgamma led to different tendencies of cyclizations. In order to modify saturated alkyl functional groups at Cgamma, complex 2 was treated with vinyl and isopropenyl Grignard reagents to form 4a and 4b. Subsequent desiylation produces 5a and 5b with terminal alkynyl hydrogen. Cyclization between Cbeta and terminal alkynyl carbon generated a six-membered ring cyclic vinylidene via 6-endo-dig pathway. Cyclic vinylidene complexes 6a and 6b were characterized by 1H, 31P, 13C, COSY, HSQC, HMBC spectra and mass analyses. Treatment of 2 in the presence of K2CO3 in alcohols yielded alkoxy substituted acetylide complexes 7a and 7b. Surprisingly, cyclization of acetylide complexes 7a and 7b each with a methoxy group revealed different pathways of C-C bond formation. To better understand the controlling factors, further alternative experiments showed that the solvent plays a key role in regioselective cyclizations of 10a and 8a. For 10a and 8a, we assume the aprotic-protic intrinsic property of solvent dominates the cyclization pathways, which are 6-endo-dig and 5-exo-dig. In addition, a similar reaction of 2 in EtOH also worked, which generated 8b and 10b. However, the regioselectivity to form vinylidene complex 10b with a five-membered ring via 5-exo-dig pathway from 7b is lower. Furthermore, cyclic vinylidene 10a and 10b are able to undergo transformation via carbyne to form the acyl complex 9 in slightly basic condition. In opposite, 8a transforms via 1,3 alkoxy shift to form methoxy carbene in chlorofom. We also studied reactivity of the acetylide complex obtained from 1,6-enyne 1. Treatment of 1 with Cp(PPh3)2RuCl in the presence of KPF6 in MeOH afforded the vinylidene complex 12. Deprotonation of 12, carried out with NaOMe in MeOH, was leading to the acetylide complex 13. Cyclization of 13 occurs between Cbeta and the vinyl carbon to form a cyclic vinylidene 14. The structure was characterized by 1H, 31P, 13C, HMBC spectra and mass analyses