1.9.1 Dess-Martin Periodinane (DMP)

The Dess-Martin Periodinane (DMP) is a hypervalent iodine compound developed by Daniel Benjamin Dess and James Cullen Martin. It is a selective oxidizing agent and works under essentially neutral conditions.

1.9.1.1 Preparation

The DMP is prepared by treating 2-iodobenzoic acid with potassium bromate and then acetylated with acetic anhydride in presence of catalytic amount of toluenesulphonic acid (Scheme 1). This reagent has indefinite shelf-life in a sealed container, however, hydrolysis occurs upon exposure to moisture.

Scheme 1

R. J. Boeckman, Jr., Encyclopedia of Reagents for Organic Synthesis, John Wiely and Sons, Inc., L. A. Paquette, Ed., New York, 1995, 7, 4982.

1.9.1.2 DMP Oxidation

DMP oxidizes alcohols to give aldehydes and ketones under neutral or near neutral conditions. The reaction is mild and the alcohols can be selectively oxidized in presence of other sensitive functional groups at room temperature (Scheme 2). There is no over oxidation of the carbonyl compounds to carboxylic acids. Furthermore, simple product isolation makes this protocol much useful.

Scheme 2

 

Mechanism
The alcohol replaces labile acetate group from the iodine to give the intermediate a that can undergo reductive elimination by oxidizing alcohol to give the carbonyl compound (Scheme 3). 

Scheme 4