A Convenient Synthesis of π-Allylpalladium Compounds from Monosubstituted Terminal Olefins

Abstract

There has been considerable recent interest in new applications of π-allylpalladium compounds in organic synthesis.^2,3 In our own work on the synthesis of prostaglandin endoperoxide analogs, we had need of π-allylpalladium compounds of the following type where

X is a functional group. W e had originally hoped to prepare these compounds directly from the corresponding terminal olefins. Unfortunately however, the most widely used methods for the direct conversion of olefins

to π-allylpalladium compounds apparently are not applicable to monosubstituted terminal olef ins,^4–8 and those which appeared applicable either gave very low yields, mixtures of π-allylpalladium compounds,¹¹ or no product at a11.¹² An equally important route to π-allylpalladium compounds employs allylic chlorides and palladium(I1) salts.^13–15 Unfortunately, allylic chlorides are difficult compounds to handle and one would prefer to avoid isolating these compounds if at all possible.