Synthesis and characterization of titanium complexes bearing sulfoxide groups and their catalytic behaviors in ethylene homo- and copolymerization
作者:Zheng Wang、Ai-Qing Peng、Xiu-Li Sun、Yong Tang
DOI:10.1007/s11426-014-5137-4
日期:2014.8
Titanium complexes derived from 2,4-di-tert-butyl-6-((2-(arylsulfinyl)phenylimino)methyl)phenol are designed and synthesized. X-ray diffraction studies reveal that the complexes adopt distorted octahedral geometry with O(phenol), N(imine), and O(sulfoxide) coordinated with titanium. Combined with modified methylaluminoxane(MMAO), the complexes exhibit moderate to high activity to afford polyethylene even at 120 °C under 1 atm ethylene pressure. The complexes also show excellent capability in copolymerization of ethylene with either 1-hexene or norbornene. Results indicate that the introduction of sulfoxide groups could open the space around central metal and favors the insertion of bulky comonomers.
Blower, Philip J.; Dilworth, Jonathan R.; Hutchinson, John P., Journal of the Chemical Society, Dalton Transactions, 1985, p. 1533 - 1542
作者:Blower, Philip J.、Dilworth, Jonathan R.、Hutchinson, John P.、Zubieta, Jon A.
DOI:——
日期:——
A high temperature investigation using microwave synthesis for electronically and sterically disfavoured substrates of the Newman–Kwart rearrangement
作者:Jonathan D. Moseley、Philip Lenden
DOI:10.1016/j.tet.2007.02.101
日期:2007.5
Electronically deactivated and/or sterically hindered substrates undergo the Newman–Kwartrearrangement (NKR) at around 300 °C, beyond the range of most convenient and safe, small-scale laboratory equipment. We report here the convenient conversions of several difficult substrates using modern microwave technology, which has proven ideal for investigating this high temperature reaction in all but the most
Role of Steric Hindrance in the Newman-Kwart Rearrangement and in the Synthesis and Photophysical Properties of Arylsulfanyl Tetrapyrazinoporphyrazines
phenol derivative with an emphasis on eliminating side reactions. Thiophenols with different 2,6-disubstitution patterns (including hydrogen, methyl, isopropyl or tert-butyl groups) were used for the synthesis of 5,6-bis(arylsulfanyl)pyrazine-2,3-dicarbonitriles that underwent cyclotetramerization leading to the corresponding zinc tetrapyrazinoporphyrazines (TPyzPz), aza-analogues of phthalocyanines. Several