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Synthesis and analysis of copper carboxylate salts ..

prepare a series of copper(II) carboxylate ..

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An expanded substrate scope and in depth analysis of the reaction mechanism of the copper(II) carboxylate promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic γ- and δ-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon-carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N-C bond is formed via intramolecular syn aminocupration and the C-C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring.

Copper (I) thiophene- 2 - carboxylate | Sigma-Aldrich
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The rapid assembly of such molecules and the search for new molecular scaffolds provides a constant challenge to the synthetic and medicinal chemist, thus, new methods of entry into these systems are especially useful. One particularly attractive method is the intramolecular carboamination reaction of alkenes.In 2004, our lab disclosed the first copper(II) carboxylate promoted intramolecular carboamination reaction of N-arylsulfonyl 2-allyl anilines (). More recently we reported further substrate versatility and diastereoselectivity, and provided an experimental analysis of the reaction mechanism.In both of these accounts, a variety of γ and δ alkenyl N-aryl sulfonamides were shown to undergo the oxidative cyclization in the presence of copper(II) carboxylates to produce the corresponding polycyclic sultams in modest to good yield. In an effort to expand the utility of the method, a variety of aryl-, vinyl-, and aliphatic γ-alkenyl amides were investigated in the copper(II) promoted carboamination reaction.

A convenient synthesis of copper(I) ..

Synthesis and Analysis of Copper Carboxylate Salts Note: Most of this lab experiment is taken from an article in the Journal of Chemical Education (1995, 72, 3, 267-269).
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The oxidation of an amide or sulfonamide to the corresponding nitrogen radical by the agency of a copper salt is, in fact, unprecedented. (It should be noted, however, that the oxidation of aliphatic amines to nitriles, imines and aldehydes by copper salts have been reported, and these reactions have been postulated to occur through both radical and two electron processes.) The oxidation of N-aryl amides with o-iodoxybenzoic acid (IBX) has, however, been reported, and the derived radicals undergo intramolecular cyclization onto variously substituted olefins. Amides derived from aliphatic amines (non-aniline) are reported to be unreactive under these conditions. In our hands, subjection of N-arylsulfonyl-o-allylaniline 1a to these reaction conditions resulted in no reaction by crude 1H NMR analysis. In comparison to the IBX promoted reaction, it is also noteworthy that the arylsulfonamides derived from aliphatic amines are not significantly less reactive than arylsulfonamides derived from anilines in the copper(II) carboxylate promoted oxidative cyclization. This fact also argues against the formation of a nitrogen radical. In addition, the lower reactivity of the internal olefins [substrate 36 () is less reactive than substrate 14 ()] indicates that steric hindrance at the terminal carbon impedes reactivity in the copper(II) carboxylate promoted reactions; by comparison, amidyl radical reactions are not impeded by substitution on the terminal alkene carbon (e.g. ). Transition metal mediated additions of nitrogens to alkenes often suffer lower reactivity with internal alkenes., We therefore conclude that the reactivity pattern observed in the copper(II) carboxylate promoted carboaminations is most consistent with a reaction mechanism that requires addition of [Cu] to the terminal alkene carbon.

The rapid assembly of such molecules and the search for new molecular scaffolds provides a constant challenge to the synthetic and medicinal chemist, thus, new methods of entry into these systems are especially useful. One particularly attractive method is the intramolecular carboamination reaction of alkenes.In 2004, our lab disclosed the first copper(II) carboxylate promoted intramolecular carboamination reaction of N-arylsulfonyl 2-allyl anilines (). More recently we reported further substrate versatility and diastereoselectivity, and provided an experimental analysis of the reaction mechanism.In both of these accounts, a variety of γ and δ alkenyl N-aryl sulfonamides were shown to undergo the oxidative cyclization in the presence of copper(II) carboxylates to produce the corresponding polycyclic sultams in modest to good yield. In an effort to expand the utility of the method, a variety of aryl-, vinyl-, and aliphatic γ-alkenyl amides were investigated in the copper(II) promoted carboamination reaction.

2-ethylhexanoate to generate copper(I) carboxylate catalysts from ..

Sigma-Aldrich offers Aldrich-682500, Copper(I) thiophene-2-carboxylate for your research needs
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The composition of compounds 1–6 was verified by elemental analysis and a ..
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