The combination of Pd catalyst and Xantphos ligand in the presence of Et(3)B nicely promotes the allylation of aldehydes with conjugated dienes to provide dienyl homoallyl alcohols in excellent yields. The reaction occurs selectively at the C-C double bond bearing higher electron density.

Tandem reaction: The Pd-catalyzed three-component coupling reaction of an allylic alcohol, terminal alkyne, and organoborane to give (E)-1-substituted 2-alkyl-1,4-pentadienes, involving geminal allylation and alkylation at the acetylenic terminal carbon, is described. Bis-diene undergoes a similar multicomponent coupling reaction with acetylene and organoborane, involving cyclization of bis-π-allylpalladium, to form trans-allyl pentadienyl cyclic and heterocyclic compounds with excellent regio- and stereoselectivities (see scheme).

No abstract

Palladium-Catalyzed Tandem Coupling Reaction of Alkyne, Conjugated Diene, and Triethylborane. -(TAKUSHIMA, D.; FUKUSHIMA, M.; SATOMURA, H.; ONODERA, G.; KIMURA*, M.; Heterocycles 86 (2012) 1, 171-180, http://dx.doi.org/10.3987/com-12-s(n)70 ; Grad. Sch. Eng., Nagasaki Univ., Nagasaki 852, Japan; Eng.) -R. Langenstrassen 18-045

Dienyl Homoallyl Alcohols via Palladium Catalyzed Ene-Type Reaction of Aldehydes with 1,3-Dienes. -The reaction occurs selectively at the C-C double bond bearing higher electron density. It provides an alternative method for formation of stereodefined β-branched Baylis-Hillman adducts in comparison to the DABCO/ DMSO protocol. -(FUKUSHIMA, M.; TAKUSHIMA, D.; KIMURA*, M.; J. Am. Chem. Soc. 132 (2010) 46, 16346-16348, http://dx.