Zr and Hf-metal-organic frameworks: Efficient and recyclable heterogeneous catalysts for the synthesis of 2-arylbenzoxazole via ring open pathway acylation reaction
作者:Linh Ho Thuy Nguyen、Trang Thi Thu Nguyen、Phuong Hoang Tran、Yoshiyuki Kawazoe、Hung Minh Le、Tan Le Hoang Doan
DOI:10.1016/j.jcat.2019.04.023
日期:2019.6
2-arylbenzoxazole under solvent free conditions. Owning the wide opening spaces structures and inherent formate sites, MOFs based on 6-connected Zr6/Hf6 node were able to identify a significantly enhanced yield in Brønsted acid catalyzed reactionsunder conventional heating and microwaveirradiation. In addition, the detailed mechanism of active sites of the ring opening acylation reaction was confirmed
Novel and efficient heterogeneous polymer supported copper catalyst for synthesis of 2-substituted Benzoxazoles from 2-Haloanilides
作者:Thachora Venu Saranya、Pambingal Rajan Sruthi、Veena Raj、Saithalavi Anas
DOI:10.1016/j.jorganchem.2021.121733
日期:2021.4
A novel polymer supported copper complex is prepared by the immobilization of copper iodide on chemically modified polyacrylonitrile and its application in heterogeneous catalysis is described. The catalyst was prepared by easy method via synthetic modification of Polyacrylonitrile (PAN) using ethylene diamine followed by the complexation with CuI. After characterization, this complex was explored
A direct base-mediated intramolecular carbon-oxygen bond formation has been developed without a transition-metal catalyst. In the presence of 2.0 equiv of K2CO3 in DMSO at 140 °C, the intramolecular cyclization of o-haloanilides affords benzoxazoles in high yields. A mechanism via an initial formation of a benzyne intermediate followed by nucleophilic addition to form the CâO bond has been proposed.
Synthesis of Benzoxazoles by an Efficient Ullmann-Type Intramolecular C(aryl)-O Bond-Forming Coupling Cyclization with a BINAM-Copper(II) Catalyst
作者:Govindasamy Sekar、Ajay Naidu
DOI:10.1055/s-0029-1218589
日期:2010.2
benzoxazoles were synthesized from the corresponding N-(2-iodophenyl)benzamides through intramolecular C(aryl)-O bond formation via Ullmann-type coupling cyclization in the presence of a catalytic amount of an easily available BINAM-copper(II) complex under very mild reaction conditions (82 ˚C). Less reactive bromo and chloro analogues of the N-(2-halophenyl)benzamides were also successfully cyclized
Novel benzoxazole compounds of the formula ##STR1## wherein R.sub.1, R.sub.2 and A are certain substituents, a process for their manufacture as well as their use as optical brighteners are disclosed.