- Synthesis of aminoisoquinolines via Rh-catalyzed [4 + 2] annulation of benzamidamides with vinylene carbonate
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A new strategy is developed for the synthesis of 1-aminoisoquinoline derivatives. This Rh(III)-catalyzed [4 + 2] annulation reaction employs benzamidines as efficient directing groups and the vinylene carbonate as an acetylene surrogate. Additionally, the reaction features broad substrate scopes and good yields, only producing carbonate anion as byproduct.
- Huang, Xin,Xu, Yingying,Li, Jianglian,Lai, Ruizhi,Luo, Yi,Wang, Qiantao,Yang, Zhongzhen,Wu, Yong
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supporting information
p. 3518 - 3521
(2021/06/12)
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- Acid-catalyzed synthesis of imidazole derivatives via N-phenylbenzimidamides and sulfoxonium ylides cyclization
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A straightforward method to synthesize imidazole derivatives from amidines and sulfoxonium ylides catalyzed by acids is reported in this study. Specifically, catalyzed by trifluoroacetic acid in DCE solvents can improve synthesis efficiency under metal-fr
- Tian, Yuan,Qin, Mingda,Yang, Xueying,Zhang, Xueguo,Liu, Yafeng,Guo, Xin,Chen, Baohua
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supporting information
p. 2817 - 2823
(2019/04/13)
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- Rhodium-catalyzed C-H activation/annulation of amidines with 4-diazoisochroman-3-imines toward isochromeno[3,4-: C] isoquinolines
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A rhodium-catalyzed C-H activation/annulation of amidines with 4-diazoisochroman-3-imines has been established to afford a series of 8-amino-5H-isochromeno[3,4-c]isoquinolines in moderate to good yields with good functional group tolerance. This reaction
- Xu, Shengbo,Qiao, Shanshan,Sun, Song,Yu, Jin-Tao,Cheng, Jiang
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p. 8417 - 8424
(2019/09/30)
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- Intramolecular alkene hydroamination and degradation of amidines: Divergent behavior of rare earth metal amidinate intermediates
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Direct N-H addition of amidines to alkenes is a highly valuable but challenging transformation that remains elusive. Now, the intramolecular hydroamidination of N-alkenylamidines is achieved by using a rare earth catalyst, which provides an efficient and atom-economical approach for substituted imidazolines and tetrahydropyrimidines. Moreover, a mild and efficient method for the catalytic degradation of amidines to give amines and nitriles is also developed. Additionally, amidine reconstruction followed by an intramolecular alkene hydroamidination strategy for the synthesis of substituted imidazolines and tetrahydropyrimidines from secondary enamines and inactive amidines has also been established, which may circumvent the need for some unavailable starting materials. The mechanistic studies prove that these reactions proceed via a key lanthanide amidinate intermediate that can undergo substrate- and amine-controlled chemodivergent transformations: intramolecular alkene insertion, nitrile extrusion, amidinate reconstruction, or a combination of the reactions. The results presented here not only demonstrate the synthetic potential and versatility of alkene hydroamidination with substrates, but also provide a good insight into the factors that promote or deter the hydroamidination of alkenes.
- Zhang, Dexing,Liu, Ruiting,Zhou, Xigeng
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p. 5573 - 5581
(2018/11/20)
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- Sulfated tungstate catalyzed activation of nitriles: addition of amines to nitriles for synthesis of amidines
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An efficient and mild method for the synthesis of amidines by direct nucleophilic addition of amines to nitriles using sulfated tungstate as heterogeneous catalyst is described. Highlight of the method is its applicability for the synthesis of amidines using a wide variety of amines including ammonia as ammonium acetate and nitriles. Catalyst is mildly acidic, stable, easy to prepare and separate from the reaction mass.
- Veer, Sachin D.,Katkar, Kamlesh V.,Akamanchi, Krishnacharya G.
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supporting information
p. 4039 - 4043
(2016/08/18)
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- Aminolysis of an N-diazeniumdiolated amidine as an approach to diazeniumdiolated ammonia
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Recent theoretical studies have suggested that the parent diazeniumdiolate ion, H2N-N(O)=NO- ( diazeniumdiolated ammonia ), might be stable enough to be isolated and that it could potentially serve as a uniquely advantageous prodrug form of bioactive nitroxyl (HNO). Here, we report on an attempt to isolate its O2-benzylated derivative by aminolysis of the C=N bond in PhC(NH2)=N-N(O)=NOBn. The reaction proved remarkably sluggish in comparison to aminolysis of unsubstituted benzamidine, and the desired product could not be isolated, apparently because of base sensitivity of the NH2 group. Consistent with this interpretation, O-benzylhydroxylamine and N2O were recovered from the reaction mixture in high yields, along with N,N′-dibutylbenzamidine. Theoretical calculations rationalize the observed slow aminolysis by demonstrating that the diazeniumdiolate group greatly suppresses the electrophilicity of the adjacent C=N carbon center, rendering attack at that position endothermic. The data provide significant insights into the challenges inherent to the pursuit of diazeniumdiolated ammonia.
- Biswas, Debanjan,Hrabie, Joseph A.,Saavedra, Joseph E.,Cao, Zhao,Keefer, Larry K.,Ivanic, Joseph,Holland, Ryan J.
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p. 4512 - 4516
(2014/06/09)
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- Construction of dihydropyrimidine skeleton using 1,2,4-trisubstituted-1,3- diaza-1,3-butadienes
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Construction of a dihydropyrimidine ring was developed that involved the cyclization of 1,3-diaza-1,3-butadienes having an N-protecting group (N-Cbz, N-Boc, N-alkyl, or N-benzyl) with α,β-unsaturated carbonyl compounds such as ethyl acrylate and p-chlorophenyl vinyl ketone. Consequently, 4-dimethylamino-2-phenyl-1,4,5,6-tetrahydropyrimidines were synthesized in good yields. Subsequently, the β-elimination of the dimethylamino group was carried out with MeI or SiO2 to afford various N-protecting-2,5- disubstituted-1,6-dihydropyrimidines in good yields. Remarkably, the use of 4-chlorophenyl vinyl ketone directly provided the dihydropyrimidine without the tetrahydropyrimidine intermediate in excellent yield.
- Cho, Hidetsura,Nishimura, Yoshio,Yasui, Yoshizumi,Yamaguchi, Masahiko
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supporting information; experimental part
p. 1177 - 1179
(2012/03/26)
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- Synthesis of novel 2-phenyl-5-substituted dihydropyrimidines using 2-phenyl-1,3-diaza-1,3-butadienes and electron-deficient olefins
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A novel synthetic method for 2,5-disubstituted dihydropyrimidines was developed. The cyclization of 1,3-diaza-4-dimethylamino-1,3-butadienes having a N-protecting group (N-Boc, N-Cbz, N-n-C4H9, N-Bn or N-Ph) with electron-deficient olefins, such as α,β-unsaturated carbonyl compounds, phenyl vinyl sulfone, and acrylonitrile was studied in detail. The cyclization smoothly proceeded to afford 4-dimethylamino-1,4,5,6- tetrahydropyrimidines or 1,6-dihydropyrimidines in good yields. The isolated 4-dimethylamino-1,4,5,6-tetrahydropyrimidines were converted to 2,5-disubstituted-1,6-dihydropyrimidines through the β-elimination of the dimethylamino group. 2,5-Disubstituted-1,4(6)-dihydropyrimidines were obtained after removal of the N-Boc or N-Cbz group. Independent tautomers of the resulting dihydropyrimidines were observed.
- Nishimura, Yoshio,Yasui, Yoshizumi,Kobayashi, Satoshi,Yamaguchi, Masahiko,Cho, Hidetsura
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experimental part
p. 3342 - 3350
(2012/07/13)
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- HIGH AFFINITY SMALL MOLECULE C5A RECEPTOR MODULATORS
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This invention relates to low molecular weight, non-peptidic, non-peptidomimetic, organic molecules that act as modulators of mammalian complement C5a receptors, preferably ones that act as high affinity C5a receptor ligands and also to such ligands that act as antagonists or inverse agonists of complement C5a receptors, preferably human C5a receptors, Preferred compounds of the invention possess one or more, and preferably two or more, three or more, four or more, or all of the following properties in that they are; 1) multi-aryl in structure (having a plurality of un-fused or fused aryl groups), 2) heteroaryl in structure, 3) orally available in vivo (such that a sub-lethal or preferably a pharmaceutically acceptable oral dose can provide a detectable in vitro effect such as a reduction of C5a-induced neutropenia) , 4) comprised of fewer than four, preferably fewer than three, or fewer than two, or no amide bonds, and 5) capable of inhibiting leukocyte chemotaxis at nanomolar concentrations and preferably at sub-nanomolar concentrations. Specifically exemplified representative compounds include, but are not limited to optionally substituted arylimidazoles, optionally substituted arylpyridyls, optionally substituted aryl-substituted cycloalkylimidazoles, optionally substituted arylpyrazoles, optionally substituted benzimidazoles, optionally substituted aryl-substituted tetrahydroisoquinolines, and optionally substituted biaryl carboxamides. This invention also relates to pharmaceutical compositions comprising such compounds. It further relates to the use of such compounds in treating a variety of inflammatory and immune system disorders. Additionally, this invention relates to the use such compounds as probes for the localization of C5a receptors.
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Page/Page column 126; 132
(2010/02/06)
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- A New Regioselective Synthesis of 1,2,5-Trisubstituted 1H-Imidazoles and Its Application to the Development of Eprosartan
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A new method is presented for the preparation of 1,2-disubstitued-1H-imidazole-5-carboxaldehydes by the reaction of N-monosubstituted amidines with 2-halo-3-alkoxy-2-propenals. The reaction is highly regioselective with ratios of 1,2,5:1,2,4-imidazolecarboxaldehydes ranging from 85:15 to 100: 0. This methodology could be extended with similar results to the synthesis of imidazole-5-nitriles by the reaction of 2-bromo-3-methoxy-2-propenenitrile with N-monosubstituted amidines.
- Shilcrat, Susan C.,Mokhallalati, Mohamed K.,Fortunak, Joseph M. D.,Pridgen, Lendon N.
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p. 8449 - 8454
(2007/10/03)
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