Palladium Catalyzed Electrophilic C2-Arylation of Azoles by Aryltriazenes in Ionic Liquid Promoted by Acidic Ionic Liquid
CHEMISTRYSELECT
Authors: Sutar, Suraj M.; Savanur, Hemantkumar M.; Patil, Chidanand; Prabhala, Pavankumar; Aridoss, Gopalakrishnan; Kalkhambkar, Rajesh G.
Abstract
A green C-H bond activation of azole based bio-pertinent substrates such as benzoxazole, benzothiazole, benzimidazole are accomplished using readily prepared 1-aryltriazenes as arylating agent. Under an optimized condition employing Pd(OAc)(2)and CuI in either hydrophilic [Bmim][BF4] or hydrophobic [Bmim][PF6] IL medium with [BMIM(SO3H)][OTf] as a promoter, these arylation reactions proceeded smoothly to afford 2-aryl substituted azoles in acceptable to better yields besides noticeable functional group tolerance. The prospective for recovery and re-use of ionic liquid solvent is demonstrated.
Architecture transition of supramolecular polymers through hierarchical self-assembly: from supramolecular polymers to fluorescent materials
POLYMER CHEMISTRY
Authors: Li, Riqiang; Chen, Wenzhuo; Yang, Ying; Li, Hui; Xu, Fenfen; Duan, Zhaozhao; Liang, Tongxiang; Wen, Herui; Tian, Wei
Abstract
In this work, three different monomers AB2, C2, and TP4 were synthesized. AB2 + C2 could self-assemble to form a supramolecular hyperbranched polymer (SHP1) based on crown ether-based host-guest interaction. Upon adding TP4 into the solution of SHP1, SHP1 transformed into a higher molecular weight supramolecular cross-linked polymer (SCP1), accompanied by a dramatic fluorescence emission enhancement due to the aggregation of the tetraphenyl ethylene core induced by supramolecular polymerization. A supramolecular gel with blue fluorescence emission was generated when the concentration of SCP1 exceeded 64 mM. Adding/removing K(+)or heating/cooling the gel could realize reversible gel-sol transition, accompanied by the decrease or enhancement of the fluorescence emission intensity. Moreover, the supramolecular gel with AIE properties showed excellent self-repairing capability.