Cross carbon-nitrogen

Jiang L, Buchwald SL (2004) Palladium-catalyzed aromatic carbon-nitrogen bond formation. In de Meijere A, Diedeiich F (eds) Metal-catalyzed cross-coupling reactions, 2nd edn. Wiley-VCH, Weinheim... 

Scheme 4) <02CC1816>. The reaction occurred selectively in the peripheral carbon-nitrogen bond, showing that this bond is more reactive than the other carbon-carbon double bonds. This can be understood by the resonance contributions to the overall structures. Figure 3 shows two such resonance structures. In the canonical form II the C=N is both cross conjugated and in an iminium form which is known to be electron-deficient and an active dienophile <02CC1816>.

The first examples of microwave-mediated solid-phase carbon-nitrogen cross-coupling reactions were reported in 1999 by the group of Combs [16], using a boronic... 

Cross-coupling reaction of aryl halides with arylamines is a straightforward method for forming a carbon-nitrogen bond and is catalyzed by a palladium complex. This methodology was applied by Kanbara, Mullen, and several groups to... 

Figure 9 Molecular packing diagrams of CA with (1) acrylonitrile (a) a crossing structure and (b) a bilayer structure with (2) methacrylonitrile (c) a crossing structure, and (d) a bilayer structure and (3) with ethyl acetate (e) Form I and (f) Form II. Hydrogen atoms are omitted for clarity. Carbon, nitrogen, and oxygen atoms are represented by open, gray and filled circles, respectively.

Figure 10 Crystal structures of CA with acetic acid (a) 1 1 crossing structure and (b) 1 2 bilayer structure. Crystal structures of CAM with acetonitrile and water (c) 1 1 1 triangular structure and (d) 1 1 2 bilayer structure. Open, gray and filled circles represent carbon, nitrogen and oxygen atoms, respectively. Hydrogen atoms are omitted for clarity.

Paul, F., Patt, J., Hartwig, J. F. Palladium-catalyzed formation of carbon-nitrogen bonds. Reaction intermediates and catalyst improvements in the hetero cross-coupling of aryl halides and tin amides. J. Am. Chem. Soc. 1994,116, 5969-5970. 

The synthesis of sodium channel inhibitor 1 [82] illustrates the utility of the /V-oxide strategy by using it not only to form the biaryl carbon-carbon bond, but also to form the C4 carbon-nitrogen bond. Diaryl ether 3, prepared by a copper catalyzed cross-coupling of 4-fluorophenol and l-bromo-4-iodobenzene [83], was coupled... 

The fluid dimer polyamides and fatty amido amines also react with phenolic resins (23). These reactions are significantly different from those of epoxy resins. With the heat-reactive phenolic resins, the aminopolyamide portions react with methylol groups. A carbon-nitrogen bond or cross-link is formed and a volatile byproduct, water, is produced. This reaction requires external heat to remove water. At temperatures near 150 °C the reaction proceeds smoothly. Since curing at elevated temperatures is required, the pot life or shelf life at room temperature is relatively long. The liquid dimer polyamide and fatty amido amines also react with alpha, beta unsaturated acids and esters (29) and with polyesters (30). The unsaturated esters reduce viscosity, lengthen useful pot life, and reduce heat of reaction. Thus, they are useful diluents when low viscosity is desired. 

A further improvement was achieved by employing 3,4,7,8-tetramethyl-1,10-phenanthroline (33) as ligand. The combination of NiCla and 33 catalyses cross-coupling of aliphatic iV-tosylaziridines and primary alkylzinc reagents under mild conditions. In this transformation the carbon-nitrogen bond cleavage mainly occurs at the less-hindered side of the aziridine (Scheme 14.40). In addition, when enantiopure benzylaziridine was... 

The aliphatic segments of the amine cross-linked resins yield more acetaldehyde than acetone. The reverse is true of the anhydride-cured resins. This is thought to be due to preferential rupture of carbon-nitrogen bonds [511] ... 

No general statement can be made about the elements that can be determined and the samples that can be analyzed, because these depend on the nuclear characteristics of the target nuclide (isotopic abundance), the nuclear reaction (cross-section and related parameters such as threshold energy and Coulomb barrier), and the radionuclide induced (half-life, radiation emitted, energy, and its intensity) for the analyte element, the possible interfering elements and the major components of the sample. CPAA can solve a number of important analytical problems in material science (e.g., determination of boron, carbon, nitrogen, and oxygen impurities in very pure materials such as copper or silicon) and environmental science (e.g., determination of the toxic elements cadmium, thallium, and lead in solid environmental samples). As these problems cannot be solved by NAA, CPAA and NAA are complementary to each other. 

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