Ligated regioselective PdII catalysis to access β-aryl-bearing aldehydes, ketones, and β-keto esters
By employing ligands in the PdII-mediated arylative isomerization of allyl alcohols, a milder and regioselective access to the versatile building blocks β-aryl aldehydes and ketones was developed. This new and chelation-controlled protocol enabled the compatibility of wide range of functionalities to generate dihydrochalcones, α-benzyl-α′- alkyl acetones, dihydrocinnamaldehydes, and α-benzyl β-keto esters (from Baylis-Hillman adducts). A practical multigram synthesis of an intermediate for Propafenone was also demonstrated. Copyright
Vellakkaran, Mari,Andappan, Murugaiah M. S.,Kommu, Nagaiah
supporting information; experimental part
p. 4694 - 4698
(2012/09/22)
Double arylation of allyl alcohol via a one-pot heck arylation- isomerization-acylation cascade
A one-pot, two-step catalytic protocol has been developed. A regioselective Heck coupling between aryl bromides and allyl alcohol leads to the generation of arylated allyl alcohols that in situ isomerize to give aldehydes, which then undergo an acylation reaction with a second aryl bromide. A variety of aryl bromides can be employed in both the initial Heck reaction and the acylation, providing easy access to a wide variety of substituted dihydrochalcones.