Copper imides

With ligand 170 (R = Bn), Fahmi reports the formation of an equal amount of byproduct, formulated as the allylic imide 171, Eq. 103. Indeed, Fahmi suggests that this is the correct structure of the same byproduct observed by Katsuki et al. (116) (cf. Section III.A.4, Structure 161). Fahmi suggests that this product may be formed by insertion of solvent in copper benzoate intermediate 172, as illustrated in Scheme 12. The generated copper imidate 174 then reacts with the allylic radical and combines to provide the allylic amination product 175 that rearranges to the observed imide 171. 

Steiner U B, Cased W R, Suter U W, Rehahn M and Schmitz L 1993 Ultrathin layers of low and high-molecular-weight imides on gold and copper Langmuir 6 3245-54... 

One important point to stress from these results is the possibihty of using copper chloride instead of copper triflate to prepare the complexes. It is well known that in organic solvents there is a dramatic counteranion effect on the activity and enantioselectivity of these catalysts. On the other hand, the rapid anion exchange produced in the ionic hquid resulted in better performance of the complexes, as the bis(triflyl)imide behaves in a similar way to the triflate counteranion. 

In the very recent past, metal complex catalysis has been used with advantage for the stereo- and enantio selective syntheses based on the Henry and Michael reactions with SENAs (454-458). The characteristic features of these transformations can be exemplified by catalysis of the reactions of SENAs (327) with functionalized imides (328) by ligated trivalent scandium complexes or mono-and divalent copper complexes (454) (Scheme 3.192). Apparently, the catalyst initially forms a complex with imide (328), which reacts with nitronate (327) to give the key intermediate A. Evidently, diastereo- and enantioselectivity of the process are associated with preferable transformations of this intermediate. 

The success of bis(oxazoline)-copper(II) catalyzed Diels-Alder reactions involving acryloylimides as dienophiles has been extended to the Michael reaction, Eqs. 204 and 205. The observed enantiofacial discrimination in the Diels-Alder reactions was expected to translate well to Michael reactions involving enolsilanes as nucleophiles. Indeed, fumarate-derived imides afford Michael adducts of enolsilanes in high enantioselectivity (240). Diastereoselectivity in these reactions may be regulated by judicious choice of thioester and enolsilane geometry to provide either diastereomer in high selectivity (>99 1 syn or 95 5 anti). 

Addition of an alkene to a compound containing a metal-H bond usually results in insertion, and it does in this case, too, to give the stabler 1° alkylmetal. Addition of CuBr to this complex might result in transmetallation, to give a C2-Cu bond. Addition of the copper compound to the unsaturated imide gives conjugate addition, perhaps by coordination of the C3=C4 tz bond and insertion into the C2-Cu bond. Workup gives the observed product. 

OpticaUy active iV-tosylsulfoximides produced in the copper-catalyzed reaction of chiral sulfoxides with tosyl azide may be hydrolyzed with strong acid (H2SO4) to optically active free sulfoximides. However, this procedure often fails and/or results in decomposition. It is interesting to note in this connection that a simple one-step method for the preparation of optically active unsubstituted sulfoximides has been reported recently by Johnson and co-workers (180). It involves the reaction between optically active sulfoxides and 0-mesi-tylsulfonylhydroxylamine and results in sulfoximides 60 of high optical purity. As expected, this imidation process occurs with retention of configuration at sulfur. 

Murase, K., Nitta, K., Hirato, T., Awakura, Y., Electrochemical behaviour of copper in trimethyl-n-hexylammonium bis((trifluoromethyl)sulfonyl)amide, an ammonium imide-type room temperature molten salt, /. Appl. Electrochem., 31, 1089, 2001. 

Flexible copper-clad laminates with nonthermoplastic polyimides were prepared in a two-step process entailing isolating the polyamic acid and then thermally imidizing to the corresponding polyimide. Plasma or thermal treatments of selected polyimides generated materials with excellent bonding strength when evaluated on laminated copper foil. 

Further examples of the functionalization of sulfur compounds with iodine(III)-nitrogen ylides include copper-catalyzed imidations of phenyl benzyl sulfide with [(sulfonylimino)iodo]benzenes possessing imidazole and pyridine rings in the sulfonyl moiety [34], and uncatalyzed tosylimidations of diaminothiocarboxylate inner salts 26 (Scheme 14) with Phi = NTs to give 27 [35]. 

This reaction allows aryl carbon-heteroatom bond formation via an oxidative coupling of arylboronic acids, stannanes or siloxanes with N-H or O-H containing compounds in air. Substrates include phenols, amines, anilines, amides, imides, ureas, carbamates, and sulfonamides. The reaction is induced by a stoichiometric amount of copper(II) or a catalytic amount of copper catalyst which is reoxidized by atmospheric oxygen. 

Nanocrystalline copper with an average crystallite size of about 50nm can be obtained without additives in the ionic liquid 1-butyl-l-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide ([BMP]Tf2N) [92], Because of the limited solubility of the tested copper compounds in this ionic liquid, copper cations were introduced into the ionic liquid by anodic dissolution of a sacrificial copper electrode. The electrodeposition of copper was also investigated in the ionic liquid... 

Anhydro-4-hydroxyoxazolium hydroxides were first obtained in 1974 by the decomposition of the a-diazoimides (295) induced by copper(II) acetylacetonate. The reaction proceeds by way of a carbene or a carbenoid species (equation 147). The triphenyl derivative is formed when the imide shown in equation (148) is treated with triethyl phosphite (82JOC723). 

In the second major class of amine derivatives, the amidic nitrogen atom can also be A-arylatcd when the sodium salt of the amides is treated with /wra-tolyllead triacetate 58 in CH2C12-DMF at 60-80 °C under mild conditions113,114 (Equations (91)-(93)). Amides as well as sulfonamides, imides, or hydantoins reacted with aryllead triacetates under copper(ll) catalysis, to afford good to excellent yields of the derived A-arylamidcs. In general, better yields were obtained when the sodium salt of the amide was used. For these amidic substrates, the reactions are... 

Section II of this paper contains a description of the mechanism of NEXAFS spectroscopy, experimental setup and the types of information that can be obtained. Section III presents examples of work by others which serve as an important basis for the interpretation of our studies, and also several experiments on oriented polymer films and Langmuir-Blodgett films. Section IV describes a study of the chemical interaction that takes place when chromium metal is evaporated onto spun polymers, including polyimide. Section V describes the results of a study of poly(amic acid) films grown by epitaxy on clean surfaces of copper and chromium, and the effect of annealing to induce imidization. 

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