- Nucleophilic Substitution at the Guanidine Carbon Center via Guanidine Cyclic Diimide Activation
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Despite the electron-deficient nature of the guanidine carbon centers, nucleophilic reactions at these sites have been underdeveloped because of the resonance stabilization of the guanidine group. We propose a guanidine C-N bond substitution strategy entailing the formation of guanidine cyclic diimide (GCDI) structures, which effectively destabilize the resonance structure of the guanidine group. In the presence of acid additives, the guanidine carbon center of GCDIs undergoes nucleophilic substitution reactions with various amines and alcohols.
- An, Taeyang,Lee, Yan
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supporting information
p. 9163 - 9167
(2021/11/24)
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- 2-Aminoquinazolines by Chan-Evans-Lam Coupling of Guanidines with (2-Formylphenyl)boronic Acids
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A new method is presented for the synthesis of 2-aminoquinazolines, which is based on a Chan-Evans-Lam coupling of (2-formylphenyl)boronic acids with guanidines. Relatively mild conditions involving the use of inexpensive CuI as a catalyst and methanol as a solvent permit the application of the method to a wide range of substrates. Nonsubstituted, N-monosubstituted, and N,N-disubstituted guanidines can be used as reactants to give the corresponding 2-aminoquinazolines in moderate yields from readily available (2-formylphenyl)boronic acids.
- Solomin, Vitalii V.,Seins, Alberts,Jirgensons, Aigars
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supporting information
p. 1507 - 1510
(2020/07/24)
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- Guanidine cyclic diimides and their polymers
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We report the formation and degradation of a unique guanidine cyclic diimide (GCDI) structure and GCDI-based polymers. The GCDI structure is readily formed under mild conditions. The X-ray crystal structure showed that the delocalized π-orbitals in the guanidine plane are significantly disrupted in the GCDI structure. Unlike amine-based imides, the GCDI structure readily degrades into the initial guanidine in protic solvents at ambient temperatures. Furthermore, poly(GCDI)s, a new category of polymers with the GCDI backbones, can be synthesized from guanidines and dianhydrides. Similar to the monomeric GCDIs, poly(GCDI)s are degraded in protic solvents unlike polyimides with high chemical stability.
- An, Taeyang,Kang, Byeongwoo,Kang, Sunyoung,Pac, Jinyoung,Youk, Jihea,Lin, Dian,Lee, Yan
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supporting information
p. 10222 - 10225
(2019/09/03)
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- Ultrasound-assisted synthesis of substituted guanidines using 1H-pyrazole-1-carboxamidine and S-methylisothiouronium sulfate under solvent-free conditions
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We have investigated ultrasound-assisted synthesis of guanidine derivatives using 1H-Pyrazole-1-carboxamidine (PyzCA) and S-substituted isothiouronium sulfate (MeITU). The guanylations of several amines are promoted by ultrasound sonication under solvent-free conditions, and proceed under mild conditions. It is of particular interest that the guanylations do not require bases in most cases.
- Fujita, Mitsue,Furusho, Yoshio
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p. 4339 - 4342
(2018/07/06)
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- New cellulose-supported reagent: A sustainable approach to guanidines
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(Chemical Equation Presented) A new cellulose-supported reagent for the synthesis of guanidine in aqueous medium is reported starting from commercially available functionalized cellulose beads. Primary and secondary amines, anilines, and amino acids were transformed to the corresponding guanidines in high yields and under very mild conditions.
- Porcheddu, Andrea,Giacomelli, Giampaolo,Chighine, Alessandra,Masala, Simonetta
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p. 4925 - 4927
(2007/10/03)
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- Total deprotection of N,N'-bis(tert-butoxycarbonyl)guanidines using SnCl4
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The total deprotection of NdV'-bis-Boc guanidines using SnCl4 proceeds smoothly in ethyl acetate at room temperature and leads to the easily isolable corresponding guanidinium chlorides.
- Miel, Hugues,Rault, Sylvain
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p. 7865 - 7866
(2007/10/03)
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- Preparation of Substituted N-Phenyl-4-aryl-2-pyrimidinamines as Mediator Release Inhibitors
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The role of immunologically released mediators, such as histamine, leukotrienes, and platelet-activating factor, is well-established for asthma and other allergic disorders.Developing therapeutic agents which would block mediator release from mast cells and other relevant cell types would provide a rational approach to asthma therapy.Using human basophil as a screen, a series of 4-aryl-2-(phenylamino)pyrimidines was found which inhibited mediator release.These compounds were prepared by condensing acetyl heterocycles with dimethylformamide dimethyl acetal to form enaminones which are cyclized with aryl guanidines to give pyrimidines.After examining a large number of analogs, N--4-(2-pyridinyl)-2-pyrimidinamine (1-27) was chosen for toxicological evaluation.
- Paul, Rolf,Hallett, William A.,Hanifin, John W.,Reich, Marvin F.,Johnson, Bernard D.,et al.
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p. 2716 - 2725
(2007/10/02)
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