This research explored the amination reaction of 1,3-bis-chloromethyl-tetramethyl-disiloxane in two different pathways. First, will discuss the synthesis of a new bipodal amino siloxane ligand which was achieved by the reaction of bis-chloromethyl-tetramethyl-disiloxane with t-BuNH3 in the presence of n-BuLi. The new ligand, of t-Butyl-[3-(t-butylamino-methyl)-1,1,3,3-tetramethyl disiloxanylmethyl]-amine (L1), is a model ligand designed to simulate the SOMC model of silica support and bipodal amido ligand that has been presented by the Basset group. Hence, developing this type of siloxane ligand and their complexes will be valuable in the synthesis of new homogenous catalyst, studying the reactivity and attempt to connect them with the SOMC examples. For this, the reaction of L1 with several Lewis acids and afforded several uncommon dimer and cluster complexes in the solid state.
The second part of this research found that heating of bis-chloromethyl-tetramethyl-disiloxane with a 4-6 equivalent of amine, affording 4-N-Alkyl-tetramethyl- oxazadisilinane as six heterocycle ring by using a new simple and neat method. Using six different amine functional groups afforded six new oxazadisilinane compounds with different alkyls substituted.
Each oxazadisilinane compound was utilized and reacted with four different acids, affording a series of twenty-one examples of new siloxane protic ionic liquids (Si-PILs). Also, the reaction of the cation with methyl iodide provided two examples of siloxane aprotic ionic liquids (Si-AILs). The new family of Si-ILs were well characterized by using NMR, mass, melting point, elemental analysis and thermal gravimetric analyses. Additionally, twelve crystals were suitable for X-ray diffraction as Si-PILs and one for Si-AILs. By studying their chemical and physical properties, a good library of the new Si-ILs has been built. Finally, one group of the new Si-PILs was used for butyl acetate esterification. The 5-X group of new Si-PILs salt was tested for esterification of butanol with acetic acid by thermal heat and under microwave irradiation. The salt 5-BF4- showed a good result in both systems with easy separation from the reaction mixture and recyclability discriminates the 5-BF4- as a good catalyst for the esterification reaction.
|Date of Award||Jul 2018|
|Original language||English (US)|
- Physical Science and Engineering
|Supervisor||Kuo-Wei Huang (Supervisor)|
- Siloxan Ionic Liquids
- Bipodal amino ligand