Carboxylic acids reactions with alkenes

There are actually three reactions called by the name Schmidt reaction, involving the addition of hydrazoic acid to carboxylic acids, aldehydes and ketones, and alcohols and alkenes. The most common is the reaction with carboxylic acids, illustrated above.Sulfuric acid is the most common catalyst, but Lewis acids have also been used. Good results are obtained for aliphatic R, especially for long chains. When R is aryl, the yields are variable, being best for sterically hindered compounds like mesi-toic acid. This method has the advantage over 18-13 and 18-14 that it is just one laboratory step from the acid to the amine, but conditions are more drastic. Under the acid conditions employed, the isocyanate is virtually never isolated. 

Reaction with Carboxylic Acid Derivatives. Reaction of (1) with carboxylic acid derivatives provides silyl ketones (3) (eq 4). The reaction 3ueld is very dependent upon the presence of a-hydrogens in the substrate lower yields are obtained when deprotonation can occur at this center. The reaction occurs with esters, lactones, acid chlorides, and the parent carboxylic acids. The resultant /3-silyl ketones can be desilylated by simple hydrolysis, or used as a substrate in a Peterson alkenation approach to enones. The use of a cerium reagent with the acid chloride has been advocated for the preparation of allylsilanes. ... 

Reaction with Carboxylic Acids The intramolecular reaction of carboxylic acids with alkenes affords unsaturated lactones (eq 14).i ... 

Cerium(IV) salts are very useful reagents for the functionalization of alkenes. In this section, only a few representative examples are shown. More examples can be found in reviews written by Nair and coworkers (Nair et al., 2002, 2004). The halogenation of alkenes with CAN has been described in section 6.7. Alkenes react with carboxylic acids in presence of cerium(IV) sulfate to yield carboxylic esters (scheme 50) (Horiuchi et al., 2003). The addition reaction follows Markovnikov s rule. The carboxylic acid also acts as solvent. This reaction provides a simple method for the preparation of carboxylic esters from alkenes. 

Other major industrial applications for hydrogen peroxide include the manufacture of sodium percarbonate and sodium perborate, used as mild bleaches in laundry detergents. It is used in the production of certain organic peroxides such as dibenzoyl peroxide, used in polymerisations and other chemical processes. Hydrogen peroxide is also used in the production of epoxides such as propylene oxide. Reaction with carboxylic acids produces a corresponding peroxy acid. Peracetic acid and meta-chloroperoxybenzoic acid (commonly abbreviated mCPBA) are prepared from acetic acid and /weto-chlorobenzoic acid, respectively. The latter is commonly reacted with alkenes to give the corresponding epoxide. 

The reaction of alkenyl mercurials with alkenes forms 7r-allylpalladium intermediates by the rearrangement of Pd via the elimination of H—Pd—Cl and its reverse readdition. Further transformations such as trapping with nucleophiles or elimination form conjugated dienes[379]. The 7r-allylpalladium intermediate 418 formed from 3-butenoic acid reacts intramolecularly with carboxylic acid to yield the 7-vinyl-7-laCtone 4I9[380], The /i,7-titisaturated amide 421 is obtained by the reaction of 4-vinyl-2-azetidinone (420) with an organomercur-ial. Similarly homoallylic alcohols are obtained from vinylic oxetanes[381]. 

Methods of synthesis for carboxylic acids include (1) oxidation of alkyl-benzenes, (2) oxidative cleavage of alkenes, (3) oxidation of primary alcohols or aldehydes, (4) hydrolysis of nitriles, and (5) reaction of Grignard reagents with CO2 (carboxylation). General reactions of carboxylic acids include (1) loss of the acidic proton, (2) nucleophilic acyl substitution at the carbonyl group, (3) substitution on the a carbon, and (4) reduction. 

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