COHALOGENATION IN ORGANIC-SYNTHESIS

The usefulness of the intermolecular cohalogenation in organic synthes is is reviewed. After a short background of this almost centenarian re action we develop some mechanistic considerations in order to explain briefly the exceptional regio-, chemo- and stereoselectivity of this s imple process, which allows the facile preparation of various bifuncti onal derivatives. Cohalogenation with oxygen and nitrogen containing n ucleophiles such as water, hydrogen peroxide, carboxylic acid derivati ves, alcohols, ethers, nitriles, amines and pseudohalogens are present ed successively in wide detail and we focus on the different applicati ons of the cohalogenated compounds. The synthetic potential of such mi xed halogenations is illustrated by the numerous examples in which the se reactions have provided powerful simplification in the functionaliz ation and in the synthesis of natural and medicinal products.