This Nobel Prize-winning (2010) palladium-catalyzed cross-coupling reaction between organohalides and organoboron compounds is a versatile four-step process, creating carbon-carbon sigma bonds: (i) Oxidative addition of the organohalide to the Pd(0) catalyst, creating a halide-Pd(II)-alkyl complex (ii) Replacement of the halide attached to the complex with the anion of the base...

Esters are hydrolyzed either by aqueous base or acid to yield carboxylic acids plus alcohols. In base-catalyzed hydrolysis (saponification), a hydroxide ion attacks the ester carbonyl to produce a tetrahedral alkoxide intermediate. Elimination of the alkoxide ion generates the carboxylic acid, which is immediately deprotonated by the alkoxide ion. An...

Sandmeyer Reaction A radical mechanism, catalytic for copper(I) salt has been proposed for the Sandmeyer reaction, which converts an aryldiazonium halide/salt to an aryl halide or an aryl pseudohalide. The required aryldiazonium halide is usually prepared from arylamines (via diazotization) using either NaNO2/hydrohalic acid or alkyl nitrites under anhydrous conditions....

The Friedel-Crafts alkylation reaction uses a Lewis acid catalyst to attach an alkyl group to an electron-rich benzene ring or derivative. First, a carbocation electrophile is generated through Lewis acid-assisted ionization of an alkyl halide. The aromatic ring then attacks the carbocation, forming a carbon-carbon bond and a new carbocation...

Benzyl groups are often used to protect alcohols in multi-step synthetic reactions. To deprotect, the benzyl ether first undergoes oxidative addition to the Pd(0) catalyst, forming a Pd(II) complex. Hydrogen coordination and transfer then facilitates the release of the alcohol. Reductive elimination expels toluene and regenerates the palladium catalyst. Reagents:...

The separation of ionic and ionizable analytes can be effectively achieved using a reversed-phase high performance liquid chromatographic (RP-HPLC) technique called ion-pair chromatography (IPC).  Used on reversed phase columns which are more efficient than columns used in ion exchange chromatography, resulting in better resolution  Sharper peak shapes and highly reproducible results even...