نتایج جستجو برای: olefin

تعداد نتایج: 2960  

2015
Cheng-Liang Zhu Jun-Shan Tian Zhen-Yuan Gu Guo-Wen Xing Hao Xu

An iron-catalyzed enantioselective and diastereoselective intramolecular olefin aminochlorination reaction is reported (ee up to 92%, dr up to 15 : 1). In this reaction, a functionalized hydroxylamine and chloride ion are utilized as nitrogen and chlorine sources, respectively. This new method tolerates a range of synthetically valuable internal olefins that are all incompatible with existing a...

Journal: :Physical chemistry chemical physics : PCCP 2013
Heejin Kim Joonho Park Yousung Jung

The application of a metal-organic framework (MOF) has expanded into the area of heterogeneous catalysis, gas storage and separation, drug delivery, and lightweight magnets. Herein, we investigate the nature of olefin and paraffin binding on Fe/MOF-74 and identify several factors that determine separation efficiency using the first-principles calculations. The calculated binding energies and ma...

Journal: :Science 2005
G H Maughan E Maughan

(1) If heated with iodine as a catalyst, the tertiary alcohol (I) readily yielded the olefin (III). (2) This olefin rearranged immediately to the dicyclic hydrocarbon (II) when digested with concentrated sulfuric acid. (3) Treated with the proper concentration of sulfuric acid, or phosphoric acid, the alcohol (I) passed immediately to the olefin (III), which on longer treatment changed to the i...

Journal: :Chemical communications 2014
Xiangqing Jia Lei Zhang Chuan Qin Xuebing Leng Zheng Huang

Iridium complexes of novel NCP pincer ligands containing pyridine and phosphinite arms have been synthesized. One Ir complex shows good catalytic activity for alkane dehydrogenation, and all complexes are highly active for olefin isomerization. A combination of the Ir complex and a (PNN)Fe pincer complex catalyzes the formation of linear alkylboronates selectively from internal olefins via sequ...

Journal: :Molecules 2016
Veronica Paradiso Chiara Costabile Fabia Grisi

The catalytic properties of olefin metathesis ruthenium complexes bearing N-heterocyclic carbene ligands with stereogenic centers on the backbone are described. Differences in catalytic behavior depending on the backbone configurations of symmetrical and unsymmetrical NHCs are discussed. In addition, an overview on asymmetric olefin metathesis promoted by chiral catalysts bearing C₂-symmetric a...

2006
Xiaohao Liu Xiaohong Li Kenji Asami

The influence of solvent on the selectivity of α-olefin in the product hydrocarbon as a function of carbon number over a 20 wt.% Co on SiO2 catalyst under the typical reaction conditions of 513 K, 4.5 MPa and H2/CO = 2 has been investigated. Hydrocarbons with different carbon numbers and molecular structures, including n-hexane, n-octane, n-decane, n-dodecane, n-hexadecane, iso-octane and decah...

Journal: :Dalton transactions 2012
Chiara Dinoi Rinaldo Poli Lionel Perrin Laurent Maron

A DFT investigation of the olefin epoxidation mechanism catalysed by the [Cp*WO(OH)(2)](+) complex with H(2)O(2) reveals that the outer sphere transfer of the hydroperoxido O(β) atom to the olefin is considerably more favourable than that of the hydroperoxido O(α) atom. The reasons for this unusual pathway are discussed.

2018
Meng Wang Mojin Chen Yunming Fang Tianwei Tan

Background The production of fuels and chemicals from renewable resources is increasingly important due to the environmental concern and depletion of fossil fuel. Despite the fast technical development in the production of aviation fuels, there are still several shortcomings such as a high cost of raw materials, a low yield of aviation fuels, and poor process techno-economic consideration. In r...

2005

Olefin fibers, also called polyolefin fibers, are defined as manufactured fibers in which the fiber-forming substance is a synthetic polymer of at least 85 wt% ethylene, propylene, or other olefin units (1). Several olefin polymers are capable of forming fibers, but only polypropylene [9003-07-0] (PP) and, to a much lesser extent, polyethylene [9002-88-4] (PE) are of practical importance. Olefi...

Journal: :Chemical communications 2008
Ritu Ahuja Sabuj Kundu Alan S Goldman Maurice Brookhart Brian C Vicente Susannah L Scott

Tandem dehydrogenation-olefin-metathesis catalyst systems, comprising a pincer-ligated iridium-based alkane dehydrogenation catalyst and a molybdenum-based olefin-metathesis catalyst, are reported to effect the metathesis-cyclooligomerization of cyclooctane and cyclodecane to give cycloalkanes with various carbon numbers, predominantly multiples of the substrate carbon number, and polymers.

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