- Direct Amidation of N-Boc- and N-Cbz-Protected Amines via Rhodium-Catalyzed Coupling of Arylboroxines and Carbamates
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N-Boc- and N-Cbz-protected amines are directly converted into amides by a novel rhodium-catalyzed coupling of arylboroxines and carbamates, replacing the traditional two-step deprotection-condensation sequence. Both protected anilines and aliphatic amines are efficiently transformed into a wide variety of secondary benzamides, including sterically hindered and electron-deficient amides, as well as in the presence of acid-labile and reducible functional groups.
- Lim, Diane S. W.,Lew, Tedrick T. S.,Zhang, Yugen
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- Modified Graphene Oxide Based Zinc Composite: an Efficient Catalyst for N-formylation and Carbamate Formation Reactions Through CO2 Fixation
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Catalytic fixation of CO2 through chemical reactions is always a challenging task of synthetic chemistry. This paper represents the design and synthesis of an eco-friendly low cost zinc metal containing heterogeneous catalyst of aminically modified Graphene Oxide. Characterization of the catalyst has been carried out by Raman and FTIR spectra, AAS, XRD, TEM, SEM, EDX and N2 adsorption desorption studies. It was found that the catalyst was very proficient for the CO2 fixation through N-formylation and carbamate formation reactions of amines. Catalytic N-formylation reaction of both aromatic and aliphatic amines gave high yield of corresponding formylated products in presence of polymethylhydrosiloxane (PMHS) as reducing agent under 1 bar CO2 pressure and mild temperature. Formation of carbamates from aniline or its derivatives and alkyl/aryl bromide with good product selectivity was also achieved under same CO2 pressure in presence of our synthesized catalyst at room temperature with solvent-free condition. The catalyst is reusable and e?cient even after six cycles.
- Khatun, Resmin,Biswas, Surajit,Islam, Sarikul,Biswas, Imdadul Haque,Riyajuddin, Sk,Ghosh, Kaushik,Islam, Sk Manirul
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supporting information
p. 1303 - 1312
(2019/01/25)
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- A catalyst-free N-benzyloxycarbonylation of amines in aqueous micellar media at room temperature
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N-Benzyloxycarbonylation of amines was carried out in aqueous micellar media. Aliphatic (open and cyclic), aromatic and heteroaromatic amines react with Cbz-Cl to give excellent yields of products. The reactions were carried out in water and at room temperature.
- Shrikhande, Janhavi J.,Gawande, Manoj B.,Jayaram, Radha V.
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p. 4799 - 4803
(2008/12/22)
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- Tyrosine kinase inhibitors. 3. Structure-activity relationships for inhibition of protein tyrosine kinases by nuclear-substituted derivatives of 2,2'-dithiobis(1-methyl-N-phenyl-1H-indole-3-carboxamide)
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A series of indole-substituted 2,2'-dithiobis(1-methyl-N-phenyl-1H- indole-3-carboxamides) were prepared and evaluated for their ability to inhibit the tyrosine kinase activity of both the epidermal growth factor receptor (EGFR) and the nonreceptor pp60(v-src) tyrosine kinase. The compounds were synthesized by conversion of appropriate 1-methyloxindoles to 1-methyl-2-indolinethiones with P2S5 followed by subsequent reaction with NaH and phenyl isocyanate and oxidative dimerization of the resulting 2,3- dihydro-N-phenyl-2-thioxo-1H-indole-3-carboxamides. The parent compound and many of the substituted analogues were moderately potent inhibitors of both kinase enzymes, but no clear relationships were seen between substitution on the indole ring and inhibitory activity. While 4-substituted compounds were generally inactive, 5-substituted derivatives with electron-withdrawing groups showed inhibitory activity. However, none of the substituted compounds showed significantly better activity than the unsubstituted parent compound. There was generally a good correlation between activity against the EGFR and pp60(v-src) kinases, but several compounds did show some specificity (>20- fold) of inhibition; 5-Cl and 5-Br derivatives preferentially inhibited pp60(v-src), while the 5-CF3 compound preferentially inhibited EGFR. Selected compounds from the series were found to inhibit the growth of Swiss 3T3 fibroblasts with IC50s in the range 2-25 μM, the most active being 4- substituted derivatives. The compounds inhibited bFGF-mediated protein tyrosine phosphorylation in intact cells more effectively than EGFR- or PDGF- mediated phosphorylation.
- Rewcastle,Palmer,Dobrusin,Fry,Kraker,Denny
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p. 2033 - 2042
(2007/10/02)
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