- Copper- and Cobalt-Catalyzed Syntheses of Thiophene-Based Tertiary Amines
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Thienylzinc halides and related compounds prepared by deprotonation followed by transmetalation were used in copper-catalyzed amination using N-benzoyloxy secondary amines. By extending the reaction to 1,5-naphthyridine, it was showed that the competitive dimer formation observed in the case of thiophenes was linked with the low stability of some thienylamines rather than homocoupling. Interestingly, thienylzinc halides and related compounds prepared by transmetalation of thienylmagnesium halides, either prepared from their bromo-precursors or generated by deprotometalation, were satisfactorily employed in cobalt-catalyzed aminations. Finally, aminothiophenes were involved in copper-catalyzed mono- and di-N-arylations, affording differently substituted di- and triphenylamines.
- Bouarfa, Salima,Gra?l, Simon,Ivanova, Maria,Langlais, Timothy,Bentabed-Ababsa, Ghenia,Lassagne, Frédéric,Erb, William,Roisnel, Thierry,Dorcet, Vincent,Knochel, Paul,Mongin, Florence
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p. 3244 - 3258
(2019/06/08)
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- N-(Benzoyloxy)amines: An investigation of their thermal stability, synthesis, and incorporation into novel peptide constructs
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A series of N-benzoyloxyamines were pyrolyzed and their decomposition temperatures correlated well with the amine architecture's ability to stabilize a N-centered radical. A variety of amine substrates were treated with a biphasic mixture of benzoyl peroxide (BPO), CH2Cl2 and an aqueous carbonate buffer (at pH 10.5). Primary and secondary amines were successfully N-benzoyloxylated in good yield. Tertiary amines and BPO gave low yields of the corresponding N-oxide and complex product mixtures, presumably via radical decomposition. Electron deficient amines (such as fluorinated aliphatic amines, α-aminoacids, α-aminoesters, and α-aminoamides) were not N-benzoyloxylated under these conditions. Instead, N-benzoylation was observed with the fluorinated amines and the reaction was sensitive to temperature and the pH of the aqueous medium. A one-pot-two-step synthesis of Nα-FMOC-L-Leu-Nβ-(benzoyloxy)-β-alanine ethyl ester, a peptide containing both an α- and a novel β-amino acid framework, was also developed.
- Nemchik, Anne,Badescu, Valentina,Phanstiel IV, Otto
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p. 4315 - 4325
(2007/10/03)
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