四[3,5-雙(三氟甲基)苯基]硼酸離子配位之鹼金族及鹼土族金屬離子的催化反應

Abstract

在本論文中，Mn+(H2O)m(BArF4-)n {M = Li+、Na+、K+、Mg2+ 和Ca2+，BArF4- = tetrakis[bis-3,5-(trifluoromethtyl)phenyl]borate}能夠催化聚合反應、縮醛的去保護、ε-caprolactone和epoxide的開環反應，還有Mannich Type 反應。 在水溶液中，Mn+(H2O)m(BArF4-)n本身就會形成聚集物，更會和有機物形成微胞，展現出疏水性效應。微胞群聚將金屬離子水合物帶進有機相中，讓金屬離子水合物發揮催化活性。在有機溶液中時，Mn+(H2O)m(BArF4-)n亦會形成聚集物釋放質子催化乙烯基醚(vinyl ether)和對甲氧基苯乙烯(p-methoxystyrene)的聚合反應。除此之外，BArF4-能夠讓聚合反應中，藉由金屬離子水合物產生的陽離子容易被其他的親核基攻擊，避免終結反應發生的功效。 在不同的反應條件下，金屬離子水合物扮演的角色也不盡相同。在苯乙烯的聚合反應中，需要一個起始劑生成碳陽離子起始聚合反應。此時，它們是路易士酸，催化碳陽離子的生成。而在縮醛的去保護反應和Mannich Type 反應中，它們則呈現Brønsted-Lowry acid的性質來進行催化。 所以，根據反應條件的不同，金屬離子水分子簇可以發揮出金屬離子的路易士酸性質或是金屬離子水合物的Brønsted-Lowry酸的特性，達到催化反應的目的。

In this thesis, it was found that Mn+(H2O)m(BArF4-)n {M = Li+, Na+, K+, Mg2+, and Ca2+ ; BArF4- = tetrakis[bis-3,5-(trifluoromethtyl)phenyl] -borate}could catalyze the polymerization reaction, deprotection of acetal, ring opening reaction of ε-caprolactone and epoxides, and Mannich type reaction. In aqueous solution, the borate salt forms aggregates particularly with organic materials, which is due to the hydrophobic effect of the aryl group on the borates. This aggregation readily includes the hydrated metal ion into the organic phase. That makes the hydrated metal ion acting as a Brønsted-Lowry acids. Mn+(H2O)m(BArF4-)n produced proton to polymerize vinyl ether and p-methoxystyrene in CH2Cl2. Additionally, BArF4- could make cation that was produced by proton more easily be attacked by another nucleophile, and avoid the termination of the polymerization. In different reaction conditions, hydrated metal ion could act different roles. In the polymerization of styrene, it was needed that an initator to start the polymerizeion. So, they acted as lewis acids to catalyze the forming of caboncation. In the deprotection of acetal, and Mannich type recation. Thus, Mn+(H2O)m(BArF4-)n promotes the polymerization of vinyl ether and p-methoxystyrene. Under different reaction conditions, the hydrated metal ions can also act as Lewis acid. With a initator, Mn+(H2O)m(BArF4-)n catalyze the polymerization of styrene.