Cis anti-Markovnikov addition

Further information on the mechanisms of these addition reactions is found in a study of the reaction of "phenylpalladium acetate with trans- and cfs-propenylbenzene 24>. The trans-isomer reacted in nearly quantitative yield at 30 °C in methanol solution to produce trans-1,2-diphenyl-l-propene. About a half of a percent yield of l,2-diphenyl-2-propene was also found. Only a trace of the Markovnikov product 1,1-diphenyl-l-propene was seen (See Chart 1). The reaction of cfs-propenyl-benzene under the same conditions produced an 85% yield of olefins containing 65% of cis- 1,2-diphenyl- 1-propene, 22% trans-1,2-diphenyl-1 -propene, 10% 2,3-diphenyl-l-propene and about 3% of 1,1-diphenyl-1-propene. The major products in both reactions are the one expected from a cis-anti-Markovnikov addition of the phenylpalladium acetate followed by a cis-elimination of "hydrodopalladium acetate . There is practically no Markovnikov addition. 

---