Vinylic substitution reactions

Abstract

Abstract Vinylically and/or allylically substituted organic compounds or tautomers or reduced forms thereof are formed when certain organometallic derivatives of Group VIII metals are reacted at 0* to about 200*, with olefinic compounds possessing at least one hydrogen on a vinylic position. The organometallic derivative should have the formula RMXa(ER3'')b, where R is an aryl, benzyl, vinylic or ethynyl group or a substituted derivative thereof with such substituents as lower alkyl groups, aryl groups, heterocyclic groups, halogen groups, nitro, cyano, carboalkoxyl, aldehyde, ketonic, dialkylamino, phenolic or hydroxylic groups. The M is a Group VIII metal, X is Br, Cl or I and ER3'' is a trivalent arsenic or phosphorus group with R'' a lower alkyl, aryl, alkoxyl, halogen or phenoxy group. The letters a and b are such as to make the molecule stable with the usual number of coordinating groups. With some of the organometallics the reaction can be carried out in a catalytic manner in the metal by including a base such as a basic tertiary amine in the reaction mixture to remove hydrogen halide from the reactants and also by having RX present to reform the RMXa(ER3'')b after each reaction cycle. A representative example is the preparation of methyl cinnamate in 85% yield from bromobenzene, methyl acrylate, tetramethylethylenediamine, one mole percent of palladium acetate and two mole percent of triphenylphosphine at 125* for 28 hours. In this example the bromobenzene, palladium acetate and triphenylphosphine from the organometallic compound transC6H5Pd(Br)(P(C6H5)3)2, under the reaction conditions.

Inventors

• 👤 Richard F Heck

Bibliographic Details