A PEG1000-DAIL[CdCl3]–toluene temperature-dependent biphasic system that regulates homogeneously catalyzed C–O coupling of organic halides with phenols and alcohols under ligand-free conditions

2011 ◽  
Vol 89 (4) ◽  
pp. 471-480 ◽  
Author(s):  
Yu Lin Hu ◽  
Xiao Yun Ma ◽  
Ming Lu
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Biphasic System ◽  
Temperature Dependent ◽  
Convenient Procedure ◽  
Organic Halides ◽  
Ligand Free

An efficient, experimentally simple, and convenient procedure for the C–O coupling of organic halides with phenols and alcohols in a PEG1000-DAIL[CdCl3]–toluene temperature-dependent biphasic system has been developed. The product can be easily isolated by a simple decantation, and the catalytic system can be recycled and reused without loss of catalytic activity.

Deactivation of arenetitanium(II) bromoalane complexes in the cyclotrimerization of butadiene

1986 ◽  
Vol 51 (12) ◽  
pp. 2751-2759 ◽  
Author(s):  
Jindřich Poláček ◽  
Helena Antropiusová ◽  
Lidmila Petrusová ◽  
Karel Mach
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Model System ◽  
Highly Active ◽  
Catalytic Stability

The C6H6.Ti(II)(AlBr4)2 (Ib) catalyst deactivates during the butadiene cyclotrimerization to give a solid containing all titanium (mostly as TiBr3) and a mixture of AlBr3 and RAlBr2 compounds dissolved in benzene. The residual cationic catalytic activity of the deactivated Ib system is due to presence of AlBr3. In contrast to TiCl3, the deactivated Ib system and the model system TiBr3 + AlBr3 are not activated by the addition of EtAlCl2 in the presence of butadiene: the highly active benzenetitanium(II) system is re-constituted only after reduction of TiBr3 with Et3Al followed by the addition of EtAlCl2. The addition of Et2AlBr to Ib accelerates the deactivation of the system. Deactivation products of this system contain mainly Ti(II) species which forms benzenetitanium(II) catalytic system after addition of EtAlCl2. All the EtAlCl2 reactivated systems produce (Z, E, E)-1,5,9-cyclododecatriene with high catalytic stability and considerable selectivity (>90%). This behaviour points to the catalysis by benzenetitanium(II) chloroalane complexes containing only low amount of bromine atoms and ethyl groups.

A copper nitride catalyst for the efficient hydroxylation of aryl halides under ligand-free conditions

2021 ◽  
Author(s):  
Hang Xu ◽  
Sho Yamaguchi ◽  
Takato Mitsudome ◽  
Tomoo Mizugaki
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalyst ◽  
Aryl Halides ◽  
High Catalytic Activity ◽  
Copper Nitride ◽  
Ligand Free

Copper nitride (Cu3N) was used as a heterogeneous catalyst for the hydroxylation of aryl halides under ligand-free conditions. The cubic Cu3N nanoparticles showed high catalytic activity, comparable to those of...

scholarly journals Ring-Opening Copolymerization of Cyclohexene Oxide and Cyclic Anhydrides Catalyzed by Bimetallic Scorpionate Zinc Catalysts

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1651
Author(s):  
Felipe de la Cruz-Martínez ◽  
Marc Martínez de Sarasa Buchaca ◽  
Almudena del Campo-Balguerías ◽  
Juan Fernández-Baeza ◽  
Luis F. Sánchez-Barba ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Mechanism ◽  
Catalytic System ◽  
Phthalic Anhydride ◽  
Ring Opening ◽  
High Selectivity ◽  
Zinc Complexes ◽  
Cyclohexene Oxide ◽  
Reaction Conditions ◽  
Cyclic Anhydrides

The catalytic activity and high selectivity reported by bimetallic heteroscorpionate acetate zinc complexes in ring-opening copolymerization (ROCOP) reactions involving CO2 as substrate encouraged us to expand their use as catalysts for ROCOP of cyclohexene oxide (CHO) and cyclic anhydrides. Among the catalysts tested for the ROCOP of CHO and phthalic anhydride at different reaction conditions, the most active catalytic system was the combination of complex 3 with bis(triphenylphosphine)iminium as cocatalyst in toluene at 80 °C. Once the optimal catalytic system was determined, the scope in terms of other cyclic anhydrides was broadened. The catalytic system was capable of copolymerizing selectively and efficiently CHO with phthalic, maleic, succinic and naphthalic anhydrides to afford the corresponding polyester materials. The polyesters obtained were characterized by spectroscopic, spectrometric, and calorimetric techniques. Finally, the reaction mechanism of the catalytic system was proposed based on stoichiometric reactions.

Third-phase catalytic activity of halogen exchange reactions in phase transfer catalytic system

1997 ◽  
Vol 52 (20) ◽  
pp. 3511-3520 ◽  
Author(s):  
Tadaatsu Ido ◽  
Takanobu Yamamoto ◽  
Gong Jin ◽  
Shigeo Goto
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Phase Transfer ◽  
Exchange Reactions ◽  
Third Phase ◽  
Halogen Exchange
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