scholarly journals Oxidative C-H/C-H Coupling of Dipyrromethanes with Azines by TiO2-Based Photocatalytic System. Synthesis of New BODIPY Dyes and Their Photophysical and Electrochemical Properties

Molecules ◽  
2021 ◽  
Vol 26 (18) ◽  
pp. 5549
Author(s):  
Maria A. Trestsova ◽  
Irina A. Utepova ◽  
Oleg N. Chupakhin ◽  
Maksim V. Semenov ◽  
Dmitry N. Pevtsov ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Quantum Yields ◽  
Luminescence Spectra ◽  
Coupling Reactions ◽  
Photocatalytic System ◽  
Absorption And Luminescence Spectra ◽  
Derivatives Of

Oxidative C-H/C-H coupling reactions of dipyrromethanes with azines in the presence of a heterophase oxidative photocatalytic system (O2/TiO2/visible light irradiation) were carried out. As a result of cyclization of obtained compounds with boron trifluoride etherate, new hetaryl-containing derivatives of 4,4-difluoro-4-boron-3a,4a-diaza-s-indacene were synthesized. For the obtained compounds, absorption and luminescence spectra, quantum yields of luminescence as well as cyclic volt-amperograms were measured.

scholarly journals TiO2 Photocatalyzed C–H Bond Transformation for C–C Coupling Reactions

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 355 ◽  
Author(s):  
Yi Wang ◽  
Anan Liu ◽  
Dongge Ma ◽  
Shuhong Li ◽  
Chichong Lu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Transition Metal Catalysis ◽  
Light Irradiation ◽  
Coupling Reactions ◽  
Metal Catalysis ◽  
Bond Functionalization ◽  
Tio2 Photocatalysis ◽  
Mild Conditions

Fulfilling the direct inert C–H bond functionalization of raw materials that are earth-abundant and commercially available for the synthesis of diverse targeted organic compounds is very desirable and its implementation would mean a great reduction of the synthetic steps required for substrate prefunctionalization such as halogenation, borylation, and metalation. Successful C–H bond functionalization mainly resorts to homogeneous transition-metal catalysis, albeit sometimes suffering from poor catalyst reusability, nontrivial separation, and severe biotoxicity. TiO2 photocatalysis displays multifaceted advantages, such as strong oxidizing ability, high chemical stability and photostability, excellent reusability, and low biotoxicity. The chemical reactions started and delivered by TiO2 photocatalysts are well known to be widely used in photocatalytic water-splitting, organic pollutant degradation, and dye-sensitized solar cells. Recently, TiO2 photocatalysis has been demonstrated to possess the unanticipated ability to trigger the transformation of inert C–H bonds for C–C, C–N, C–O, and C–X bond formation under ultraviolet light, sunlight, and even visible-light irradiation at room temperature. A few important organic products, traditionally synthesized in harsh reaction conditions and with specially functionalized group substrates, are continuously reported to be realized by TiO2 photocatalysis with simple starting materials under very mild conditions. This prominent advantage—the capability of utilizing cheap and readily available compounds for highly selective synthesis without prefunctionalized reactants such as organic halides, boronates, silanes, etc.—is attributed to the overwhelmingly powerful photo-induced hole reactivity of TiO2 photocatalysis, which does not require an elevated reaction temperature as in conventional transition-metal catalysis. Such a reaction mechanism, under typically mild conditions, is apparently different from traditional transition-metal catalysis and beyond our insights into the driving forces that transform the C–H bond for C–C bond coupling reactions. This review gives a summary of the recent progress of TiO2 photocatalytic C–H bond activation for C–C coupling reactions and discusses some model examples, especially under visible-light irradiation.

An effective photothermal dual-responsive Pd1Cu4/CexOy catalyst for Suzuki–Miyaura coupling reactions under mild conditions

2020 ◽  
Vol 44 (9) ◽  
pp. 3794-3801
Author(s):  
Bo Liu ◽  
Tong Xu ◽  
Chunping Li ◽  
Jie Bai
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Coupling Reactions ◽  
Suzuki Reactions ◽  
Mild Conditions ◽  
Dual Responsive

A Pd1Cu4/CexOy catalyst can efficiently catalyze Suzuki reactions under both heating and visible light irradiation conditions.

General Method of Preparation of N-[(S)-(3-Hydroxy-2-phosphonomethoxypropyl)] Derivatives of Heterocyclic Bases

1993 ◽  
Vol 58 (5) ◽  
pp. 1151-1163 ◽  
Author(s):  
Petr Alexander ◽  
Antonín Holý
Keyword(s):  
Sodium Salt ◽  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Cesium Carbonate ◽  
Analogous Reaction ◽  
Sodium Salts ◽  
Heterocyclic Bases ◽  
Derivatives Of ◽  
General Method ◽  
Methanolic Ammonia

Reaction of (R)-1-O-p-toluenesulfonyl-1,2,3-propanetriol (IV) with N-trimethylacetylimidazole (II) afforded (R)-1-O-p-toluenesulfonyl-3-O-trimethyacetyl-1,2,3-propanetriol (V) which was reacted with dimethoxymethane in the presence of phosphorus pentoxide to give (R)-2-O-methoxymethyl-1-O-p-toluenesulfonyl-3-O-trimethyacetyl-1,2,3-propanetriol (VI). Compound VI was treated with acetic anhydride and boron trifluoride etherate and the obtained 2-acetoxy derivative VII reacted with bromotrimethylsilane to give the intermediary bromomethyl ether VIII. Compound VIII on reaction with tris(2-propyl) phosphite afforded (R)-2-O-bis(2-propyl)phosphonomethyl-1-O-p-toluenesulfonyl-3-O-trimethyacetyl-1,2,3-propanetriol (IX). Condensation of synthon IX with sodium salts of adenine, 2,6-diaminopurine, or with cytosine, 6-azacytosine or 2-chloroadenine in the presence of cesium carbonate, afforded fully protected diesters X and XIIIb which on methanolysis and reaction with bromotrimethylsilane gave N-[(S)-(3-hydroxy-2-phosphonomethoxypropyl)] derivatives of adenine (XIa), 2- chloroadenine (XIb), 2,6-diaminopurine (XIc), cytosine (XIVa) and 6-azacytosine (XIVb). In an analogous reaction, sodium salt of 4-methoxy-2-pyrimidone reacted with compound IX to give an intermediate XIIIa which on treatment with methanolic ammonia and subsequent deblocking under the same conditions also afforded the cytosine derivative XIVa. Sodium salt of 2-amino-6-chloropurine was in this way converted into the corresponding 2-aminopurine derivative XVIII. Deprotection of this compound gave 9-(S)-(3-hydroxy-2-phosphonomethoxypropyl)-2-aminopurine (XIX).

Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: synthesis of propargyl alcohols and α-ketoesters

2019 ◽  
Vol 55 (58) ◽  
pp. 8438-8441 ◽  
Author(s):  
Ke Ni ◽  
Ling-Guo Meng ◽  
Hongjie Ruan ◽  
Lei Wang
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Coupling Reactions ◽  
Reaction Atmosphere ◽  
Propargyl Alcohols

The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere.

scholarly journals Visible-light-driven CO2 reduction on a hybrid photocatalyst consisting of a Ru(ii) binuclear complex and a Ag-loaded TaON in aqueous solutions

2016 ◽  
Vol 7 (7) ◽  
pp. 4364-4371 ◽  
Author(s):  
Akinobu Nakada ◽  
Takuya Nakashima ◽  
Keita Sekizawa ◽  
Kazuhiko Maeda ◽  
Osamu Ishitani
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Binuclear Complex ◽  
Co2 Reduction ◽  
Light Irradiation ◽  
Photocatalytic System ◽  
Visible Light Driven ◽  
Hybrid Photocatalyst

A hybrid photocatalytic system consisting of a Ru(ii) binuclear complex and Ag-loaded TaON can reduce CO2 to HCOOH by visible light irradiation even in aqueous solution (TONHCOOH = 750, ΦHCOOH = 0.48%).

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