27693-38-5Relevant academic research and scientific papers
Design of High-Performance Pyridine/Quinoline Hydrazone Photoswitches
Mravec, Bernard,Budzák, ?imon,Medved', Miroslav,Pa?teka, Luká? F.,Slavov, Chavdar,Sa?mannshausen, Torben,Wachtveitl, Josef,Ko?í?ek, Jozef,Hegedüsová, Lea,Filo, Juraj,Cigáň, Marek
, p. 11633 - 11646 (2021/08/20)
The design of P-type photoswitches with thermal stability of the metastable form of hundreds of years that would efficiently transform using excitation wavelengths above 350 nm remains a challenge in the field of photochromism. In this regard, we designed and synthesized an extended set of 13 pyridine/quinoline hydrazones and systematically investigated the structure-property relationships, defining their kinetic and photoswitching parameters. We show that the operational wavelengths of the pyridine hydrazone structural motif can be effectively shifted toward the visible region without simultaneous loss of their high thermal stability. Furthermore, we characterized the ground-state and excited-state potential energy surfaces with quantum-chemical calculations and ultrafast transient absorption spectroscopy, which allowed us to rationalize both the thermal and photochemical reaction mechanisms of the designed hydrazones. Whereas introducing an electron-withdrawing pyridyl moiety in benzoylpyridine hydrazones leads to thermal stabilities exceeding 200 years, extended π-conjugation in naphthoylquinoline hydrazones pushes the absorption maxima toward the visible spectral region. In either case, the compounds retain highly efficient photoswitching characteristics. Our findings open a route to the rational design of a new family of hydrazone-based P-type photoswitches with high application potential in photonics or photopharmacology.
Room Temperature Metal-Catalyzed Oxidative Acylation of Electron-Deficient Heteroarenes with Alkynes, Its Mechanism, and Application Studies
Sharma, Shweta,Kumar, Mukesh,Vishwakarma, Ram A.,Verma, Mahendra K.,Singh, Parvinder Pal
, p. 12420 - 12431 (2018/10/20)
Herein, we report an original one-step, simple, room-temperature, regioselective Minisci reaction for the acylation of electron-deficient heteroarenes with alkynes. The method has broad functional group compatibility and gives exclusively monoacylated products in good to excellent yields. The mechanistic pathway was analyzed based on a series of experiments confirming the involvement of a radical pathway. The 18O-labeling experiment suggested that water is a source of oxygen in the acylated product, and head space GC-MS experiment shows the C-C cleavage occurs via release as CO2.
2-Pyridyl and 3-pyridylzinc bromides: direct preparation and coupling reaction
Kim, Seung-Hoi,Rieke, Reuben D.
supporting information; experimental part, p. 3135 - 3146 (2010/06/13)
A facile synthetic approach to the direct preparation of 2-pyridyl and 3-pyridylzinc bromides has been demonstrated using Rieke zinc with 2-bromopyridine and 3-bromopyridine, respectively. A variety of different electrophiles have been coupled with the resulting organozinc reagents to give the corresponding cross-coupling products in moderate to good yields.
A facile synthetic route for 2-pyridyl derivatives: direct preparation of a stable 2-pyridylzinc bromide and its copper-free and pd-catalyzed coupling reactions
Kim, Seung-Hoi,Rieke, Reuben D.
supporting information; experimental part, p. 5329 - 5331 (2009/12/06)
Direct preparation of 2-pyridylzinc bromide has been developed. Interestingly, the subsequent coupling reactions with acid chlorides have been carried out without any transition metal catalyst. 2-Pyridylaryl compounds, symmetrical and unsymmetrical 2,2′-b
Ketone synthesis under neutral conditions. Cu(I) diphenylphosphinate-mediated, palladium-catalyzed coupling of thiol esters and organostannanes
Wittenberg, Ruediger,Srogl, Jiri,Egi, Masahiro,Liebeskind, Lanny S.
, p. 3033 - 3035 (2007/10/03)
(Matrix presented) A versatile approach to ketone synthesis is described. The reaction relies on the palladium-catalyzed, copper diphenylphosphinate-mediated coupling of thiol esters with organostannanes under neutral reaction conditions. This reaction complements the previously described coupling of thiol esters with boronic acids that used dual thiophilic-borophilic activation methodology.
