- Synthesis of N,O-acetals by net amide C[sbnd]N bond insertion of aldehydes into N-acyl phthalimides and N-acyl azoles
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We found that N-acyl phthalimides and several N-acylated azoles are capable of reacting with aldehydes to form O-acyl-N,O-acetals in an apparent amide C[sbnd]N bond insertion. In the context of N-acyl phthalimides, the reaction is mediated by substoichiometric amounts of sodium iodide and potassium phthalimide. DFT computations supported a proposed mechanism and provided insights into the effect of the alkali metal additive. This strategy could be used to prepare a myriad of N,O-acetals from a range of aldehydes. A one-pot procedure was also developed in which N-acyl phthalimide was generated in situ prior to forming the N,O-acetal product. The one-pot strategy was used to demonstrate that activated amides derived from imidazole, pyrazole, (benzo)triazole, and tetrazole are also amenable substrates. Collectively, these studies provide an approach to the synthesis of a variety of N,O-acetals under mild conditions from inexpensive starting materials.
- Enright, Robert N.,Grinde, Jeffrey L.,Wurtz, Lincoln I.,Paeth, Matthew S.,Wittman, Tekoa R.,Cliff, Emily R.,Sankari, Yessra T.,Henningsen, Lucas T.,Tan, Chuchen,Scanlon, Joseph D.,Willoughby, Patrick H.
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p. 6397 - 6408
(2016/09/23)
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- Selectivities in acylation of primary and secondary amine with diacylaminoquinazolinones and diacylanilines
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The diacylaminoquinazolinones are highly selective acylating agents for primary amines in the presence of secondary amines. The chemoselective N-acetylation reagents have been investigated using 2-substituted N,Ndiacylaminoquinazolinones (DAQs) and 2-substitued-N-diacylanilines (DAAs). Determination of the selectivity ratios have been made by comparison of the crude product in each case with authentic samples of the amide products using NMR spectroscopy. The control experiments in which pairs of amines compete for acetyl chloride show some selectivity but not comparable with that of DAQs and DAAs selectivity. When the DAQs, DAAs and acetyl chloride react with mixtures of pyrrolidine and piperidine, they give amides in the corresponding ratios. The DAQs 1 and 2 react entirely with diethylamine without any competitive reaction with diphenylamine. The high level of chemoselectivity has also been observed when the 1 and 2 react exclusively with the ethanolamine without any competitive reaction with diethanolamine. Moreover, 1 and 2 react with succinimide without any competitive reaction with phthalimide.
- Al-Sehemi, Abdullah G.,Al-Amri, Reem S. Abdul-Aziz,Irfan, Ahmad
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p. 1115 - 1121
(2014/10/15)
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- Synthesis and evaluation of some variants of the Nefkens' reagent
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A series of N-substituted phthalimides have been prepared in an effort to explore synthetic variants of the Nefkens' reagent. Three N-acylphthalimides [R = -CH3, -CH2CH3, and -C(CH3) 3] were prepared and employed for the protection of a series of representative amines. In addition, an N-methanesulfonylphthalimide and N-(diethylphosphoryl)phthalimide were also prepared. It was determined that among the phthalimides that were prepared N-propanoylphthalimide was the most effective reagent for the protection reaction.
- Goodman, Cassie A.,Hamaker, Christopher G.,Hitchcock, Shawn R.
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supporting information
p. 6012 - 6014
(2013/10/22)
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- A nonresonated orthogonally twisted amide
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The structure of N-pivaloylphthalimide was studied by IR, 13C NMR and UV spectroscopies, and X-ray analysis. The C(O)-N bond is orthogonally twisted, and the bond length is as long as that of C-N single bond.
- Yamada, Shinji,Nunami, Noriko,Hori, Kayako
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p. 451 - 452
(2007/10/03)
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- REAGENTS AND SYNTHETIC METHODS. 29. N-ACYLPHTHALIMIDES FROM CARBOXYLIC ACIDS AND PHOSPHOROUS REAGENTS UNDER PHASE TRANSFER CONDITIONS
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N-acylphthalimides are obtained from carboxylic acids and potassium phthalimide by means of phenyl dichlorophosphoridate or diphenylphosphorophthalimide under phase transfer conditions.
- Lago, J. M.,Palomo, C.
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p. 653 - 658
(2007/10/02)
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