Carbonylation reaction schematic representation

Figure 1 Schematic representation of a possible mechanism for the Cojr catalyzed carbonylation of methanol. Organic reactions involving Mel and MeCOI are omitted (see Fig. 3).

FIGURE 10.9 Schematic representation of reactions of carbonyl oxides with water. 

FIGURE 3.13 Schematic representation of (a) cyanogen bromide reaction, (b) cyclic rranr-2,3-carbonate activation method, (c) triazine activation method, and (d) carbonylation reaction. 

Schematic representation of the possible stages in the hydrolysis of Gly-L-Tyr by carboxy-peptidase A. It is probable that the carbonyl carbon of the substrate becomes tetrahedrally bonded as the reaction proceeds, but it is uncertain at what stage of the reaction the proton is added to the NH group of the susceptible peptide bond, (a) Productive binding mode, (b) General base attack by water upon the carbonyl carbon of the substrate, (c) Nucleophilic attack by Glu-270 upon the carbonyl carbon of the substrate. Taken from Ref. [33) with permission...

In what appears to be a dramatically different process, carboxylic adds that are resistant to attack by sulfuric add (H2SO4) can undergo substitution on the carbon of the carbonyl of the hydroxyl group (-OH) by the azido group (-N3) (in a process called the Schmidt reaction). While it is occasionally possible to isolate the acid azide, rearrangement to the corresponding isocyanate is common. A schematic representation in concert with available experimental data for the prcx ess of azide formation and subsequent rearrangement is shown in Scheme 9.120 for the case of benzenecarboxylic acid (benzoic acid). It is particularly important to note that in contrast to the typical formation of a tetrahedral intermediate so common for the... 

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