- Iridium-Catalyzed Asymmetric Hydrogenation of Tosylamido-Substituted Pyrazines for Constructing Chiral Tetrahydropyrazines with an Amidine Skelton
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Dinuclear triply chloro-bridged iridium(III) complexes bearing chiral diphosphine ligands catalyze the asymmetric hydrogenation of tosylamido-substituted pyrazines to give the corresponding chiral tetrahydropyrazines with an amidine skeleton in high yield and with high enantioselectivity. Addition of N,N-dimethylanilinium bromide enhanced the catalytic activity of the iridium complexes and also increased the enantioselectivity of the products by trapping the hydrogenated amine products with HBr from N,N-dimethylanilinium bromide. The amidine skeleton of the products could be transformed to give chiral piperazinones and piperazines without loss of enantioselectivity. (Figure presented.).
- Higashida, Kosuke,Nagae, Haruki,Mashima, Kazushi
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supporting information
p. 3949 - 3954
(2016/12/30)
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- Direct arylation of n-heteroarenes with aryldiazonium salts by photoredox catalysis in water
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A highly effective visible light-promoted "radical-type" coupling of N-heteroarenes with aryldiazonium salts in water has been developed. The reaction proceeds at room temperature with [Ru(bpy)3]Cl 2×6 H2O as a photosensit
- Xue, Dong,Jia, Zhi-Hui,Zhao, Cong-Jun,Zhang, Yan-Yan,Wang, Chao,Xiao, Jianliang
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supporting information
p. 2960 - 2965
(2014/03/21)
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- Chemical synthesis of coelenterazine and its analogs: New route by four segment-couplings
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A novel and improved synthetic route includes four segment-couplings toward coelenterazine and its analogs as luminescent molecules. Regio- and chemo-selective cross coupling reactions using palladium catalysts with 5-iodo-3-bromo-2-aminopyrazine have enabled providing various aminopyrazine derivatives having different substituents. The improved synthesis of coelenterazine and its analogs employed advanced condensation with the aminopyrazines using various keto-acetal segments, which resulted in much higher yields to give the final imidazopyrazinone heterocycles than the previous method using keto-aldehydes.
- Chou, Chun-Ming,Tung, Yu-Wen,Lin, Meng-I,Chan, Diana,Phakhodee, Wong,Isobe, Minoru
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p. 1323 - 1339
(2013/08/15)
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- New compounds, pharmaceutical compositions and uses thereof
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The invention relates to new compounds of the formula I to their use as medicaments, to methods for their therapeutic use and to pharmaceutical compositions containing them.
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Page/Page column 52
(2012/09/05)
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- IMIDAZO[1,2-α]PYRAZIN-3(7H)-ONE DERIVATIVES BEARING A NEW ELECTRON-RICH STRUCTURE
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The present invention relates to compound of formula I : and their use as chemiluminescent and/or bioluminescent reagents.
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Page/Page column 29
(2011/02/24)
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- A new class of pyrazolopyridine nucleus with fluorescent properties, obtained through either a radical or a Pd arylation pathway from N-azinylpyridinium N-aminides
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(Chemical Equation Presented) The synthesis of dipyridopyrazole and pyridopyrazolopyrazine derivatives - both of which incorporate a 3-aryl moiety - can be achieved in moderate yields by intramolecular radical arylation of pyridinium N-aminides using tris(trimethylsilyl)silane and azobisisobutyronitrile. Improved results were obtained on using Pd direct arylation in conjunction with microwave irradiation. A preliminary study into the fluorescent properties of the target compounds is also reported.
- Abet, Valentina,Nunez, Araceli,Mendicuti, Francisco,Burgos, Carolina,Alvarez-Builla, Julio
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scheme or table
p. 8800 - 8807
(2009/04/11)
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- Catechol derivatives of aminopyrazine and cell protection against uvb-induced mortality
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A series of 5-aryl- and 3,5-bis-aryl-2-amino-1,4-pyrazine derivatives 4 and 6, and related imidazolopyrazinones 7, has been synthesized, the aryl groups of which are catechol and/or phenol substituents. These compounds, tested against human keratinocyte c
- Cavalier, Jean-Francois,Burton, Maggi,Dussart, Frederique,Marchand, Cecile,Rees, Jean-Francois,Marchand-Brynaert, Jacqueline
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p. 1037 - 1044
(2007/10/03)
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