林英智 教授臺灣大學：化學研究所郭怡君Kuo, Yi-ChunYi-ChunKuo2007-11-262018-07-102007-11-262018-07-102007http://ntur.lib.ntu.edu.tw//handle/246246/51856一系列於末端接有乙烯基之釕金屬丙二烯錯合物{[Ru]=C=CHC(Ar)2CH2CH=CH2}BF4成功被製備出來。室溫下，將錯合物3a ([Ru] = CpRu(dppp), Ar = Ph) 溶於三氯甲烷之中，則3a會馬上進行歧化反應逐漸轉變成4a。當有一乙烯基鍵結在丙二烯基上,分子內的兩個碳碳雙鍵會馬上發生[2+2]的環化加成反應 (cycloaddition)。會產生這樣的結果主要推測與立體效應和電子效應有關，進而產生分子內的歧化反應 (metathesis)。在兩個相鄰位置的苯基對位位置上接有一甲氧基的衍生物3a”和4a”也可利用類似的質子化反應 (protonation) 合成，唯有錯合物3a’ ([Ru] = CpRu(PPh3)2, Ar2 = fluorenyl) 可以穩定於溶液中，不會進行上述反應，如將其溶於四氫呋喃溶液加熱至沸騰則會分解產生無法鑑定的化合物。加鹼將錯合物4a進行去質子化反應即可得到中性的金屬炔基錯合物6a，利用MeOTf將錯合物6a進行烷基加成反應 (alkylation) 合成陽離子釕金屬丙二烯錯合物7a。另外一方面，當接有一甲基於末端不飽和鍵的錯合物3b溶於三氯甲烷溶液中會自行進行一環化反應形成一含有環狀allene官能基的錯合物5b。其中有趣的是，當錯合物7a溶於三氯甲烷溶液中與錯合物3b溶於三氯甲烷溶液中所得到的產物是相同的。在本篇論文中將會探討此項反應 (7a-->5b) 所可能進行的反應途徑。然而,利用碳13標記實驗可以得知其中兩個有標記的碳是直接鍵結在一起的，由此實驗結果可以確定7a轉變成5b並不是經由簡單的環化反應再進行1,3-氫原子轉移 (1,3-hydrogen shift) 這樣的反應途徑。此外，在本篇論文中也嘗試在末端接上三鍵，利用相同方法將錯合物 [Ru]C≡CC(Ar)2CH2C≡CH (2c) 進行質子化 (protonation) 以合成 {[Ru]=C=CHC(Ar)2CH2C≡CH}BF4 (3c)，然而錯合物3c亦會轉變成 {[Ru]=C=CHCH2C(Ar)2C≡CH}BF4 (4c)，推測可能是經由炔基在金屬上進行π配位交換所導致的結果。若再多接上一個CH2，合成{[Ru]=C=CHC(Ar)2CH2CH2CH=CH2}BF4 (3d, 3d’ and 3d”)，則此結構會穩定存在於溶液之中。因此推測丙二烯基與末端的不飽和鍵確實可以進行一些分子內的反應，但是gem-diphenylmethylene 官能基需位於適當的立體位置方可進行。A series of ruthenium vinylidene complexes {[Ru]=C=CHC(Ar)2CH2CH=CH2} BF4 containing terminal vinyl group were prepared. In chloroform, the cationic complex 3a ([Ru] = CpRu(dppp), Ar = Ph) gradually transforms into 4a at room temperature via a metathesis process. The reaction takes place as soon as 3a is dissolved in solution. With the presence of a tethering terminal vinyl group bound to the vinylidene ligand, the [2+2] cycloaddition of two C=C double bonds readily occurred. It seems that intricate steric or electronic demand is required for an intramolecular metathesis to take place. Analogous complexes 3a” and 4a” ([Ru] = CpRu(PPh3)2, Ar = para-C6H4OMe) containing methoxy group at the para-position of gem-diphenyl group were similarly obtained from protonation of the corresponding acetylide complexes via formation of vinylidene intermediate. But only complex 3a’ ([Ru] = CpRu(PPh3)2, Ar2 = fluorenyl) is stable in solution, and decomposed to unidentified complex when heated to reflux in THF. Deprotonation of complex 4a in the presence of base gives neutral acetylide complex 6a. Addition of electrophiles at Cβ of σ-alkynyl complexes has been described as one of the most versatile entries into vinylidene derivatives. Thus, the alkylation of 6a with MeOTf causes formation of the cationic ruthenium vinylidene complex 7a. On the other hand, at room temperature in chloroform solution, complex 3b with an additional methyl group spontaneously undergoes a cyclization process to give complex 5, which contains coordinated cyclic allene ligand. Interestingly, in chloroform solution complex 7a follows the same route as that of 3b. Proposed pathways for the transformation from 7a to 5b are described. However, the 13C labeling experiments show that in complex 5b the two labeled carbon atoms are directly bonded. This result indicates that the transformation does not proceed via the pathway of simple cyclization followed by 1,3-hydrogen shift. We could not experimentally distinguish differences between these two pathways. In addition, protonation of the acetylide complex with a tethering terminal alkynyl group [Ru]C ¡CC(Ar)2CH2C≡CH (2c) generates the vinylidene complex {[Ru]=C=CHC(Ar)2CH2C≡CH}BF4 (3c) which again undergoes a transformation to give {[Ru]=C=CHCH2C(Ar)2C≡CH}BF4 (4c) possibly via a π-coordinated alkynyl complex followed by hydrogen and metal migration. No similar transformation is observed for the analogues 3c’ and 3c”. With an extra methylene group, complex {[Ru]=C=CHC(Ar)2CH2CH2CH=CH2}BF4 (3d, 3d’ and 3d”) are stable. The presence of a gem-diphenylmethylene moiety at the vinylidene ligand with the appropriate terminal vinyl or alkynyl group along with the proper steric environment implements such a novel reactivity in the ruthenium vinylidene complexes.CONTENTS Structure and Numbering of Complexes I Reaction Scheme IV Scheme 1. Synthesis of Ruthenium Acetylide Complexes 2 and Corresponding Vinylidene Complexes 3 Scheme 2. Intramolecular Transformation of Ruthenium Vinylidene Complexes Scheme 3. Reversiblity of Metathesis of Ruthenium Vinylidene 中文摘要 VII Abstract XI Chapter 1. Introduction 1 1-1. Metal Allenylidene Complexes 1-2. Metal Vinylidene Complexes 1-3. Cycloisomerixations of 1,5-Enynes 1-4. Motivation of the Thesis Chapter 2. Synthesis of Acetylide Complexes from Corresponding Allenylidene complexes 14 2-1. Preparation of Ruthenium Allenylidene Complexes 2-2. Synthesis of Ruthenium Acetylide Complexes Chapter 3. Reactivity of a Terminal Vinyl Group with Vinylidene Ligand in Ruthenium Complexes 35 3-1. Metathesis of the Vinylidene Ligand with a Terminal Vinyl Group 3-2. Ring Closure of the Alkenyl-Vinylidene Moiety 3-3. Reaction of Vinylidene Complexes with a Terminal Alkynyl Group 3-4. Reaction of the Vinylidene Ligand with an Extra Methylene Group Chapter 4. Rerversibility of Ruthenium Vinylidene Complexes Tethering a Terminal Vinyl Group 68 4-1. Alkylation of Ruthenium Acetylide Complexes 4-2. Ring Closure of the Alkenyl-Vinylidene Moiety Chapter 5. Summary and Concluding Remarks 82 Chapter 6. Experimental Section 84 References 118 Appendix 1254086664 bytesapplication/pdfen-US釕金屬丙二烯錯合物[2+2]環化加成反應Ruthenium vinylidene[2+2] cycloadditionthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51856/1/ntu-96-R94223039-1.pdf