Acyl iodides in organic synthesis: XI. Unusual N-C bond cleavage in tertiary amines

Acyl iodides in organic synthesis. Reactions with morpholine, piperidine, and N-hydrocarbylpiperidines

“…Our results (Schemes 3-5) are very consistent with those reported previously for reactions acyl iodides with tertiary amines [1]. In both cases, quaternary ammonium salt is formed as intermediate via addition of acyl iodide at the nitrogen atom of N-hydrocarbylpiperidine.…”

“…We previously showed [1] that acyl iodides react with excess primary and secondary amines in a way similar to acyl chlorides (but considerably more readily) to give the corresponding carboxylic acid amides and initial amine hydroiodides. In contrast, reactions of acyl iodides with tertiary amines occur under mild conditions in the absence of a catalyst via cleavage of N-C bond in the amine and formation of the corresponding N,N-disubstituted carboxylic acid amides and alkyl iodides (Scheme 1).…”

“…The reactions of acyl iodides with N-methyl-and N-ethylpiperidines at a molar ratio of 1 : 2 in methylene chloride at room temperature involved mainly cleavage of the exocyclic N-C bond, which is typical of their reactions with other tertiary amines [1] panied to an insignificant extent by cleavage of the endocyclic N-C bond, leading to N-alkyl-N-(5-iodopentyl) amides (yield 1.7 and 3.4% for R = Me and Ph, respectively; Scheme 4). No analogous side process was observed with N-ethylpiperidine.…”

“…Taking into account that no cleavage of N-C Ph bond occurs in reactions of acyl iodides with N,N-disubstituted anilines [1], we examined their reactions with N-phenylpiperidine at a molar ratio of 1 : 1 in benzene at 80°C. As might be expected, the products were the corresponding N-(5-iodopentyl)-N-phenyl-substituted amides which were formed as a result of cleavage of the endocyclic N-C bond (Scheme 5).…”

Aqueous-Medium Carbon–Carbon Bond-Forming Radical Reactions Catalyzed by Excited Rhodamine B as a Metal-Free Organic Dye under Visible Light Irradiation

“…White LED (400-700 nm, 1000 ml) was used. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Substrates 1 39 , 19 40 , 20 41 , 21 42 , 22 43 , 27 44 and 29 45 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 25 temperature. The stirring reaction mixture was irradiated with white LED lamp (1000 lm) at room temperature.…”