| 摘要: | 以二苯胺類（HNPh2）/鹵化苯/碘化銅/1,10-二氮雜菲（Phen）/叔丁醇鹼（MOtBu, M=Li, Na, K）進行銅（I）催化碳-氮偶合反應系統已被研究多年，但是對於其銅（I）催化錯合物還是有所爭論，主要以[Phen-Cu-NPh2]與[Cu(NPh2)2]-為主。為了釐清此爭論，首先我們移去Phen這項變因，研究銅（I）如何進行催化。由DFT理論計算的結果指出，質子轉移（proton transfer, PT）平衡: MOtBu + HNPh2 ⇌ MNPh2 + HOtBu , GPT，影響了MNPh2在反應系統中的濃度，進而影響反應速率的快慢。因此我們直接使用MNPh2/鹵化苯/碘化銅進行實驗，以移去平衡所產生的干擾，其產率為LiNPh2 > NaNPh2 > KNPh2，這與我們所預測的催化物種M[Cu(NPh2)2]，其氧化加成反應活化能之結果相符合。另一方面，計算配位基置換（ligand exchange, LC）平衡: [Phen-Cu-NPh2] + MNPh2 ⇌ M[Cu(NPh2)2] + Phen , GLC，其結果GLC = -7.02 ~ -11.12 kcal/mol，表示Phen存在時，依然是以M[Cu(NPh2)2]為主要的存在物種。並且從MNPh2/鹵化苯/碘化銅/Phen催化實驗，Phen的加入反而會造成產率的下降，打破Phen會增加反應性的迷思。;The C-N cross coupling catalyzed by NPh2H/ArI/CuI/1,10-Phenan- throline (phen)/MOtBu (M=Li, Na, K) system has been studied for many years. But the argument of Cu(I)-complex catalyst, which are [phen-Cu-NPh2] and M[Cu(NPh2)2], were still not stop. In order to clarify this argument, first we removed Phen to study Cu(I)-catalyzed mechanism. By density functional theory (DFT) studies, the proton transfer (PT) equilibrium, MOtBu + HNPh2 ⇌ MNPh2 + HOtBu, affects MNPh2 concentration, further the reaction rate is affected. Therefore, we directly used MNPh2/ArI/CuI system to remove the PT’s interferences, the result that the order of yield is LiNPh2 > NaNPh2 > KNPh2 corresponds with the oxidation-addition-activation-energy of M[Cu(NPh2)2], which were predicted our calculations. On the other hand, the calculated ligand exchange (LC) equilibrium, [Phen-Cu-NPh2] + MNPh2 ⇌ M[Cu(NPh2)2] + Phen, GLC, the results are GLC = -7.02 ~ -11.12 kcal/mol, which means that M[Cu(NPh2)2] is main species even if Phen is present. According to adding Phen accompanied decreasing yield in MNPh2/ArI/CuI/Phen experiments, this results breaking the myth of Phen enhanced reactivity. |
