- Novel Amide-Directed Hydrocarbonylation and Double Carbonylation of N-Allylamides
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The rhodium-catalyzed hydroformylation and palladium-catalyzed hydroesteryfication of N-allylamides give isoaldehyde (1) and isoester (5), respectively, with good regioselectivity through chelation control while the rhodium- and Co2Rh2(CO)12-catalyzed reactions of an N-methallylamide give a novel double carbonylation product (10) and a pyrrolidine (11), respectively, with exellent selectivity.
- Ojima, Iwao,Zhang, Zhaoda
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- DECONSTRUCTIVE FUNCTIONALIZATION METHODS AND COMPOUNDS
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Disclosed herein, inter alia, are deconstructive functionalization methods and compounds made using the same.
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Paragraph 0501; 0503
(2020/01/31)
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- The oxidative dealkylation of tertiary amides: Mechanistic aspects
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N-(But-3-enyl)-N-methylbenzamide 14a undergoes microsomal oxidation by rat liver microsomes to yield both N-methyl- and N-(but-3-enyl)benzamides 18a and 19, the products of N-dealkylation. Cyclic products, that could be derived from a carbon-centered radical formed by hydrogen atom abstraction from the N-methyl group, were not observed. When generated independently, this carbon-centred radical underwent cyclisation, the 5-exo-trig mode being preferred to 6-endo-trig by a factor of 5. In contrast, N-(but-3-ynyl)-N-methylbenzamide 15 undergoes microsomal oxidation to yield the products of dealkylation 18a and 23 and also N-benzoylpiperidone 24. Dealkylation is preferred by factor of 3 and the piperidone accounts for ca. 45% of the reaction at the N-methyl group. Piperidone formation is consistent with the generation of a carbon-centred radical α- to the amide nitrogen atom during dealkylation and implies that cyclisation proceeds preferentially via the 6-endo-dig mode. Generated independently the radical undergoes cyclisation by both 5-exo-dig and 6-endo-dig modes, the former being favoured by a factor of 10. Similarly, N,N-dimethylacrylamide 26 and N-methyl-N-(3-pyridyl)acrylamide 27 undergo microsomal oxidation to form, via the 5-endo-trig cyclisation mode, 3-hydroxy-N-methyl-2-pyrrolidone 33 and 3-hydroxycotinine ? 34, respectively, confirming the intermediacy of a carbon-centred radical in the dealkylation process. Attempts to trap N-acyliminium ions during microsomal dealkylation failed. Thus, although N,N-dimethylaniline 35 reacts in the presence of NaCN to form N-cyanomethyl-N-methylaniline 37 (Nu=CN), N,N-dimethylbenzamide undergoes dealkylation without forming N-cyanomethyl-N-methylbenzamide. Similarly, microsomal reaction of N,N-dimethylaniline in the presence of NaBD4 gives rise to multiple incorporation of deuterium atoms into the methyl groups of the starting material, whereas N,N-dimethylbenzamide undergoes dealkylation but with no such deuterium incorporation into the starting material. Further, microsomal oxidation of N,N-dimethylsalicylamide 38 yields N-methylsalicylamide 40 with no evidence for the formation of N-methyl-2,3-dihydro-4H-1,3-benzoxazin-4-one 39, the potential product of intramolecular cyclisation of the phenolic oxygen atom onto the putative N-aroylmethylene iminium ion.
- Iley, Jim,Tolando, Roberto
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p. 2328 - 2336
(2007/10/03)
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- Synthesis of azetidine, pyrrolidines and piperidine by intramolecular cyclization of ω-Azidoboranes.
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This paper describes the development of efficient routes to azetidine, pyrrolidines and piperidines by creation of a carbon-nitrogen bond.Two complementary syntheses of these heterocycles were studied : the cyclization of ω-azidoboronic esters by treatment with boron trichloride, and the one pot hydroboration of an ω-azidoalkene and intramolecular reductive alkylation.The scope and limitations of these two promising approaches are reported.Keywords: azides / boronic esters / boranes / intermolecular cyclization / azetidine / pyrrolidine / piperidine / pyrrolizidine
- Jego, J. M.,Carboni, B.,Vaultier, M.
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p. 554 - 565
(2007/10/02)
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