scholarly journals Synthesis of nitrogen heterocycles via α-aminoalkyl radicals generated from α-silyl secondary amines under visible light irradiation

2014 ◽  
Vol 50 (64) ◽  
pp. 8900-8903 ◽  
Author(s):  
Kazunari Nakajima ◽  
Mai Kitagawa ◽  
Yuya Ashida ◽  
Yoshihiro Miyake ◽  
Yoshiaki Nishibayashi
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Carbonyl Compounds ◽  
Nitrogen Heterocycles ◽  
Light Irradiation ◽  
Secondary Amines ◽  
One Pot

We have succeeded in the visible light-mediated synthetic use of α-aminoalkyl radicals derived from α-silyl secondary amines toward addition to α,β-unsaturated carbonyl compounds. The resulting γ-aminocarbonyl compounds are converted into γ-lactams and pyrroles in a one-pot process.

Visible photostability of some ruthenium and platinum phthalocyanines in water and in the presence of organic substrates

2010 ◽  
Vol 14 (06) ◽  
pp. 499-508 ◽  
Author(s):  
Manuela Carchesio ◽  
Lucia Tonucci ◽  
Nicola d'Alessandro ◽  
Antonino Morvillo ◽  
Piero Del Boccio ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Carbonyl Compounds ◽  
Furfuryl Alcohol ◽  
Phenylacetic Acid ◽  
Water Soluble ◽  
Light Irradiation ◽  
Organic Substrates ◽  
Visible Spectra ◽  
Trapping Agent

Water-soluble, metal-tetrasubstituted phthalocyanines ( -SO3H , MPcS and -COOH , MPcC) of platinum and ruthenium were synthesized and their photostability to visible light irradiation was determined. For the ruthenium phthalocyanines, the characteristic visible Q band of the phthalocyanines was almost totally suppressed after five days of irradiation. The platinum derivatives were instead more resistant to photodegradation, and the Q band did not decrease by more than 25%. The addition of carbonyl compounds to the phthalocyanine solution in water (at concentrations at least 1400-fold those of the phthalocyanines) dramatically accelerated the photobleaching of these phthalocyanine complexes. PtPcS turned from blue to green and to colorless with one day of visible-light irradiation in the presence of acetone. This effect decreased with the increase in molecular weight of the ketones (from acetone to 2-pentanone). The addition of alcohols (i.e. 1-butanol) or other organics (i.e. phenylacetic acid) did not affect the photostability of these metal-tetrasubstituted phthalocyanines. Dioxygen also had an important role, as when the solutions of phthalocyanines were carefully deaerated before irradiation, the visible spectra were preserved. The platinum phthalocyanines, as with the palladium analogs, sensitize the photoproduction of 1O2 , as shown by the formation of endoperoxide and its rearranged products in the presence of furfuryl alcohol (a singlet oxygen trapping agent).

One-pot preparation of AgBr/α-Ag2WO4 composite with superior photocatalytic activity under visible-light irradiation

2020 ◽  
Vol 586 ◽  
pp. 124079 ◽  
Author(s):  
Raja Arumugam Senthil ◽  
Sedahmed Osman ◽  
Junqing Pan ◽  
Abrar Khan ◽  
Viengkham Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
One Pot

Copper-Catalyzed Photoinduced Radical Domino Cyclization of Ynamides and Cyanamides: A Unified Entry to Rosettacin, Luotonin A, and Deoxyvasicinone

Synthesis ◽  
2018 ◽  
Vol 50 (15) ◽  
pp. 3022-3030 ◽  
Author(s):  
Gwilherm Evano ◽  
Hajar Baguia ◽  
Christopher Deldaele ◽  
Eugénie Romero ◽  
Bastien Michelet
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Nitrogen Heterocycles ◽  
Light Irradiation ◽  
Radical Species ◽  
Efficient Procedure ◽  
Efficient Access ◽  
Luotonin A ◽  
Alkyl Iodides

A general and efficient procedure for the copper-catalyzed photoinduced radical domino cyclization of ynamides and cyanamides providing an efficient access to complex tri-, tetra- and pentacyclic nitrogen heterocycles is reported. Upon visible light irradiation in the presence of catalytic amounts of [(DPEphos)(bcp)Cu]PF6 and an amine, a range of unactivated aryl and alkyl iodides were shown to be smoothly transformed to the corresponding radical species, initiating the radical domino cyclization. This procedure provides a unified entry to rosettacin, luotonin A, and deoxyvasicinone that could be efficiently prepared in a limited number of steps.

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