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1.
Chem Commun (Camb) ; 55(74): 11095-11098, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31460525

RESUMO

The electrophilic borylation of 2,5-diarylpyrazines results in the formation of boron-nitrogen doped dihydroindeno[1,2-b]fluorene which can be synthesized using standard Schlenk techniques and worked up and handled readily under atmospheric conditions. Through transmetallation via diarylzinc reagents a series of derivatives were synthesized which show broad visible to near-IR light absorption profiles that highlight the versatility of this BN substituted core for use in optoelectronic devices. The synthesis is efficient, scalable and allows for tuning through changes in substituents on the planar heterocyclic core and at boron. Exploratory evaluation in organic solar cell devices as non-fullerene acceptors gave power conversion efficiencies of 2%.

2.
Dalton Trans ; 47(3): 734-741, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29239418

RESUMO

The reactions of 1-bora-7a-azaindenide anions, prepared in moderate to excellent yields by reduction of the appropriate 1-bora-7a-azaindenyl chlorides with KC8 in THF, with alkyl halides and carbon dioxide were studied. With alkyl halides (CH2Cl2, CH3I and BrCH(D)CH(D)tBu), the anions behave as boron anions, alkylating the boron centre via a classic SN2 mechanism. This was established with DFT methods and via experiments utilizing the neo-hexyl stereoprobe BrCH(D)CH(D)tBu. These reactions were in part driven by a re-aromatization of the six membered pyridyl ring upon formation of the product. Conversely, in the reaction of the 1-bora-7a-azaindenide anions with CO2, a novel carboxylation of the C-2 carbon alpha to boron was observed. Computations indicated that while carboxylation of the boron centre was kinetically feasible, the products of B-carboxylation were not thermodynamically favored relative to the observed C-2 carboxylated species, which were formed preferably due to the generation of both C-C and B-O bonds. In these products, the pyridyl ring remains non-aromatic, in part accounting for the observed reversibility of carboxylation.

3.
Dalton Trans ; 45(14): 5920-4, 2016 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-26583306

RESUMO

Polycyclic aromatic hydrocarbons in which one or more CC units have been replaced by isoelectronic BN units have attracted interest as potentially improved organic materials in various devices. This promise has been hampered by a lack of access to gram quantities of these materials. However, the exploitation of keystone reactions such as ring closing metathesis, borylative cyclization of amino styrenes and electrophilic borylation has lead to strategies for access to workable amounts of material. These strategies can be augmented by judicious postfunctionalization reactions to diversify the library of materials available. This Frontier article highlights some of the recent successes and shows that the long promised applications of BN-doped PAHs are beginning to be explored in a meaningful way.

4.
Ann Pharmacother ; 39(12): 2056-64, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16278258

RESUMO

OBJECTIVE: To review the efficacy and safety of first- and newer-generation antihistamines for the management of allergic rhinitis and chronic idiopathic urticaria (CIU), with a focus on management in the pharmacy. DATA SOURCES: A literature review was performed using MEDLINE (1966-October 2005), with no time or language restrictions. Key words or phrases used were histamine, antihistamine(s), first- and second-generation, allergic rhinitis, chronic idiopathic urticaria, quality of life, impairment, sedation, cost-effectiveness, astemizole, cetirizine, desloratadine, diphenhydramine, fexofenadine, loratadine, hydroxyzine, ketotifen, and mizolastine. Additional references were found in the bibliographies of the articles cited. STUDY SELECTION AND DATA EXTRACTION: Clinical trials and other experimental studies of the use of antihistamines for the management of allergic rhinitis and CIU were selected. Review papers and guidelines were also included. DATA SYNTHESIS: First-generation antihistamines are effective at ameliorating the symptoms of allergic rhinitis and CIU; however, they are associated with adverse effects due to a lack of selectivity for the histamine H(1)-receptor and an ability to bind to cerebral H(1)-receptors. Newer-generation agents, in general, possess high H(1)-receptor selectivity and a low tendency to cross the blood-brain barrier, while maintaining efficacy. In general, safety at elevated doses has been demonstrated for the newer antihistamines, although higher rates of sedation and impairment have been reported with increasing doses for some agents. CONCLUSIONS: Pharmacists can play an important role in the management of allergic rhinitis and CIU by considering the relative advantages of newer-generation agents when reviewing treatment options.


Assuntos
Antagonistas dos Receptores Histamínicos/uso terapêutico , Rinite Alérgica Sazonal/tratamento farmacológico , Urticária/tratamento farmacológico , Doença Crônica , Análise Custo-Benefício , Antagonistas dos Receptores Histamínicos/efeitos adversos , Humanos , Rinite Alérgica Sazonal/economia , Rinite Alérgica Sazonal/fisiopatologia , Urticária/economia
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