- Investigation of Masked N-Acyl-N-isocyanates: Support for Oxadiazolones as Blocked N-Isocyanate Precursors
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In contrast to carbon-substituted isocyanates that are common building blocks, N-substituted isocyanates remain underdeveloped and reports on their N-acyl derivatives (i. e. amido-isocyanates) are exceedingly rare. Herein, amido-isocyanates were investiga
- Gagné-Monfette, William,Vincent-Rocan, Jean-Fran?ois,Lutes, Owen C.,O'Keefe, Geneviève F.,Jeanneret, Alexandria D. M.,Blanger, Claire,Ivanovich, Ryan A.,Beauchemin, André M.
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supporting information
p. 14051 - 14056
(2021/09/14)
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- Design and discovery of new antiproliferative 1,2,4-triazin-3(2H)-ones as tubulin polymerization inhibitors targeting colchicine binding site
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Thirty-five new colchicine binding site inhibitors have been designed and synthesized based on the 1,2,4-triazin-3(2H)-one nucleus. Such molecules were synthesized through a cascade reaction between readily accessible α-amino ketones and phenyl carbazate
- Eissa, Ibrahim H.,Dahab, Mohammed A.,Ibrahim, Mohamed K.,Alsaif, Nawaf A.,Alanazi,Eissa, Sally I.,Mehany, Ahmed B.M.,Beauchemin, André M.
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- Intermolecular aminocarbonylation of alkenes using concerted cycloadditions of iminoisocyanates
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The aminocarbonylation of alkenes is a powerful method for accessing the β-amino carbonyl motif that remains underdeveloped. Herein, the development of intermolecular aminocarbonylation reactivity of iminoisocyanates with alkenes is presented. This includes the discovery of a fluorenone-derived reagent, which was effective for many alkene classes and facilitated derivatization. Electron-rich substrates were most reactive, and this indicated that the LUMO of the iminoisocyanate is reacting with the HOMO of the alkene. Computational and experimental results support a concerted asynchronous [3 + 2] cycloaddition involving an iminoisocyanate, which was observed for the first time by FTIR under the reaction conditions. The products of this reaction are complex azomethine imines, which are precursors to valuable β-amino carbonyl compounds such as β-amino amides and esters, pyrazolones, and bicyclic pyrazolidinones. A kinetic resolution of the azomethine imines by enantioselective reduction (s = 13.43) allows access to enantioenriched products. Overall, this work provides a new tool to convert alkenes into β-amino carbonyl compounds.
- Bongers, Amanda,Clavette, Christian,Gan, Wei,Gorelsky, Serge I.,Betit, Lyanne,Lavergne, Kaitlyn,Markiewicz, Thomas,Moon, Patrick J.,Neves, Nicolas Das,Obhi, Nimrat K.,Toderian, Amy B.,Beauchemin, Andrei M.
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p. 1175 - 1194
(2017/11/14)
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- Tuning the Annulation Reactivity of Vinyl Azides and Carbazates: A Divergent Synthesis of Aza-pyrimidinones and Imidazoles
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A divergent cascade annulation has been developed using readily available vinyl azides and carbazates with a wide range of substituents. Vinyl azides were successfully applied as bifunctional partners to prepare aza-pyrimidinones via 6-ring closure with c
- Shao, Jiaan,Liu, Xingyu,Shu, Ke,Tang, Pai,Luo, Jing,Chen, Wenteng,Yu, Yongping
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supporting information
p. 4502 - 4505
(2015/09/28)
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- Synthesis of 6-carboxylated phenanthridines by oxidative alkoxycarbonylation-cyclization of 2-isocyanobiphenyls with carbazates
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An iron-catalyzed synthesis of 6-carboxylated phenanthridines starting with readily prepared isocyanides and carbazates was developed. Reactions occurred via addition of alkoxycarbonyl radicals to the isocyanide group and subsequent intramolecular cyclization.
- Wang, Gao,Chen, Shan-Yong,Yu, Xiao-Qi
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supporting information
p. 5338 - 5341
(2015/01/09)
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- AMINO-QUINOXALINE AND AMINO-QUINOLINE COMPOUNDS FOR USE AS ADENOSINE A2A RECEPTOR ANTAGONISTS
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Compounds of the Formula (I), where W represents CH or N; and Q represents -CN, -C(=NOH)NH2, -CONHR1 or various herein described heterocyclic radicals; as well as pharmaceutically acceptable salts, solvates, esters and prodrugs thereof are adenosine A2a receptor antagonists and, therefore, are useful in the treatment of central nervous system diseases, in particular Parkinson''s disease.
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Page/Page column 70
(2009/10/22)
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- Ortho substituent effects on transfer of aryl groups from oxygen to carbon in adducts from diaryloxycarbenes and DMAD
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Diaryloxycarbenes, generated by thermolysis of 2,2-diaryloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazolines in benzene, reacted with dimethyl acetylenedicarboxylate (DMAD) to afford triesters. The triesters arose by aryl-group transfer from oxygen to carb
- Lu, Xiaosong,Warkentin, John
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p. 228 - 234
(2007/10/03)
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- Diaryloxycarbenes from oxadiazolines
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Symmetric and unsymmetric 2,2-diaryloxy-5,5-dimethyl-Δ3-1,3,4-oxadiazolines were synthesized by oxidative cyclization of aryloxycarbonyl hydrazones of acetone with lead tetraacetate and subsequent treatment of the product mixture with a phenol in acidic solution. Thermolysis of the oxadiazolines in benzene solution at 110°C afforded carbonyl ylide intermediates that cyclize, in part, to the corresponding 2,2-diaryloxyoxirane intermediates. The oxiranes, which were not observed, are required to account for the 1,1-diaryloxy-2-methylpropenes (ketene acetals) that were isolated. Most of the carbonyl ylides fragment to acetone and diaryloxycarbenes. The latter form dimers (tetraaryloxyethenes) or they can be trapped with phenols to form orthoformates. Diphenoxycarbene was also trapped with dimethyl acetylenedicarboxylate (DMAD). The method appears to be the first for generating the parent diphenoxycarbene under relatively mild conditions in solution, and the only one to date for generating unsymmetrically substituted diaryloxycarbenes. Minor competing fragmentations of the oxadiazolines to 2-diazopropane and the appropriate diaryl carbonates, were also observed.
- Lu,Reid,Warkentin
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p. 319 - 327
(2007/10/03)
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- Synthesis of ring-substituted phenyl hydrazinecarboxylates and study of their protonation in dimethyl sulfoxide solutions
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The pKa values of nineteen phenyl hydrazinecarboxylate hydrochlorides R-C6H4OCONHNH2.HCl (R = H, 3-and 4-Cl, 3-and 4-O2N, 4-Me) and their 1-methyl or 2-methyl derivatives were determined by potentiometric titration with tetrabutylammonium hydroxide in DMSO. IR spectra of the hydrazinecarboxylates and their hydrochlorides revealed that the hydrazinecarboxylate protonation occurs at N2. The methods of synthesis of phenyl hydrazinecarboxylate and their N-methyl derivatives were optimized.
- Vlasak, Petr,Parik, Patrik,Klicnar, Jiri,Mindl, Jaromir
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p. 793 - 802
(2007/10/03)
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