N carbonylation

Chlorkohlen-oxyd, n. carbonyl chloride, -oxyd-ather, m. ethyl chloroformate. -saure, /. chlorocarbonic acid (chloroformic acid, CICOOH). -sMureamtd, n. chlorocarbonyl amide (carbamyl chloride, H2NCOCI). -stoff, m. carbon chloride, carbon tetrachloride (sometimes with the adj. vierfach). 

Kohlensaure,/. carbonic acid carbon dioxide, -anhydrid, rt. carbonic anhydride (carbon dioxide), -ausscheidung,/. (Physiol.) c Tbon dioxide excretion, -bestimmer, m. apparatus for determining carbon dioxide, -brot, n, aerated bread, -chlorid, n. carbonyl chloride, -entwickelung,/. evolution of carbon dioxide, -ester, m. carbonic ester, -flasche, /. carbon dioxide cylinder, -gas, n, carbonic add gas (carbon dioxide), -gehalt, m. carbon dioxide content. 

Note. The alternative name using a substituent prefix (see 2-Carb-35.1) is 2-amino-1,2-N-carbonyl- 1,2-dideoxy-1 -/V-phenyl-a-D-glucopyranosylamine... 

Al-Mulla, E.A.J., Yimus, W.M.Z., Ibrahim, N.A. and Abdul Rahman, M.Z. 2009. Synthesis and characterization of N,N -carbonyl difatty amides from pahn oil. Journal of Oleo Science 58 467-471. 

Protonation of an imidazolide increases the electron-withdrawing effect of the heterocycle and, in this way, enhances the reactivity of the N-carbonyl group toward nucleophilic attack. A number of retinoates have been synthesized by this method. 1361... 

In spectroscopy we may distinguish two types of process, adiabatic and vertical. Adiabatic excitation energies are by definition thermodynamic ones, and they are usually further defined to refer to at 0° K. In practice, at least for electronic spectroscopy, one is more likely to observe vertical processes, because of the Franck-Condon principle. The simplest principle for understandings solvation effects on vertical electronic transitions is the two-response-time model in which the solvent is assumed to have a fast response time associated with electronic polarization and a slow response time associated with translational, librational, and vibrational motions of the nuclei.92 One assumes that electronic excitation is slow compared with electronic response but fast compared with nuclear response. The latter assumption is quite reasonable, but the former is questionable since the time scale of electronic excitation is quite comparable to solvent electronic polarization (consider, e.g., the excitation of a 4.5 eV n — n carbonyl transition in a solvent whose frequency response is centered at 10 eV the corresponding time scales are 10 15 s and 2 x 10 15 s respectively). A theory that takes account of the similarity of these time scales would be very difficult, involving explicit electron correlation between the solute and the macroscopic solvent. One can, however, treat the limit where the solvent electronic response is fast compared to solute electronic transitions this is called the direct reaction field (DRF). 49,93 The accurate answer must lie somewhere between the SCRF and DRF limits 94 nevertheless one can obtain very useful results with a two-time-scale version of the more manageable SCRF limit, as illustrated by a very successful recent treatment... 

Many of these problems have been removed through studies using exchange-inert complexes, particularly those incorporating Co(III) centers. In the 20-year period following 1967 studies with preformed complexes of the type cis-[Co(N)4(OH/H)(AAOR)]2+/3+ and [Co((N)4 (AAOR)]3+ (N)4 = (en)2, AA = Gly, 0-Ala, R = Me, Et, i-Pr) have allowed precise information to be acquired (43) and Table III lists rate data for the latter N carbonyl-O-chelated esters. What has been established for these systems may be summarized as follows. 

The IR spectra and their analysis of a variety of 13CO substituted ris-CsH5M(CO)n carbonyls and their derivatives (including CS)... 

The commonest modern method for determining the degree of hydration is to measure the intensity of the broad n- carbonyl absorption band at about 280 m/x, which disappears on hydration. Early measurements (Schou, 1926, 1929 Harold and Wolf, 1929, 1931) show considerable discrepancies, but the results of later workers are in reasonable agreement. The main uncertainty lies in the value to be assigned to the maximum extinction coefficient of the unhydrated carbonyl compound, which varies between 12 and 80 for different compounds. This is commonly taken as the value measured in a non-hydroxylic solvent such as hexane or cyclohexane, but this is not strictly valid, since the intensities of n-n- transitionsvary somewhat with the solvent (see e.g. Dertooz and Nasielki, 1961) moreover, since the shape of the band and the value of e are also solvent-dependent it may make some difference whether the extinction coefficients are compared at the same wavelength, at the respective maxima, or in terms of the band area. Special difficulties arise... 

Chromophore - the unsaturated building blocks of colour, i.e. -N=N-, carbonyl and nitro groups etc. (see also chromogen). 

Thus, the observations that (a) dienes quench the photoreduction reaction (b) the isomerization and dimerization of dienes is sensitized by the it,n carbonyl triplet and (c) there is a lack of photocycloaddition products with dienes, taken in conjunction with the relative energy levels of carbonyl compounds and dienes, form a consistent picture. 

Carbon dioxide (C02) can interact easily with several N-nucleophiles. Such interaction results in an activation of the heterocumulene, and has a great synthetic relevance as it is a key step towards the carboxylation or, more generally, the car-bonylation of the N-donor substrate and the synthesis of a variety of N-carbonyl compounds. 

The fixation of C02 by amines or, more generally, by N-nucleophiles opens an entry into a large variety of N-carbonyl organic compounds through the synthesis of a new N-C bond. The relevant processes may play key roles in the development of a new sustainable chemistry, as in these reactions C02 acts as a green carbonyl source in place of phosgene. 

Aromatic C with side chain hydroxylation and N-substituted aromatic C C=C-OH c=o R-(C=0)-R C=N, C-N Carbonyl C in aromatic ring Aromatic C attached to amide group Phenol C Aryl ethers and ketones Carbonyl C Pyrimidine C Is—Jt 286.0-287,4h,i k-°- -UA,-v... 

Much information about protein absorption can be obtained by measuring the electrochemical isotherm, the 0 - csoln relation at constant temperature for a series of fixed potentials. One takes the protein (P) as absorbing fast upon the metal, and transferring n electrons, corresponding to n carbonyl interactions. The dissociation reaction is taken to be rate determining. Then (Roscoe, 1996) ... 

Most of the reactions and properties of 1-substituted imidazoles have been discussed earlier in this review. Apart from the utilization of the readily removable benzyl substituent in synthetic procedures leading to 2-substituted imidazoles, perhaps the mostexciting advances have stemmed from the reactions of the 1 -acylimidazoles (imidazolides) which are extremely reactive in such nucleophilic reactions as hydrolysis and alcoholysis.12 The use of such compounds as N,N -carbonyl-diimidazole in peptide synthesis is now commonplace. The silicon-nitrogen bond in N-trimethylsilylimidazoles is also extremely reactive, so reactive that it is attacked by a-halogenocarboxylic esters.361... 

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