2497-23-6Relevant articles and documents
Ni- and pd-catalyzed synthesis of substituted and functionalized allylic boronates
Zhang, Ping,Roundtree, Ian A.,Morken, James P.
supporting information; scheme or table, p. 1416 - 1419 (2012/06/01)
Two highly efficient and convenient methods for the synthesis of functionalized and substituted allylic boronates are described. In one procedure, readily available allylic acetates are converted to allylic boronates catalyzed by Ni/PCy3 or Ni/PPh3 complexes with high levels of stereoselectivity and in good yields. Alternatively, the borylation can be accomplished with commercially available Pd catalysts [e.g., Pd 2(dba)3, PdCl2, Pd/C], starting with easily accessed allylic halides.
Mechanistic investigations of bipyrimidine-promoted palladium-catalyzed allylic acetoxylation of olefins
Lin, Bo-Lin,Labinger, Jay A.,Bercaw, John E.
experimental part, p. 264 - 271 (2009/10/23)
Several pyridine-like ligands were found to improve Pd(OAc) 2-catalyzed allylic oxidation of allylbenzene to cinnamyl acetate by p-benzoquinone in acetic acid. The best ligand examined, bipyrimidine, was used to identify the catalyst precursor for this system, (bipyrimidine)Pd(OAc) 2, which was fully characterized. Mechanistic studies suggest the reaction takes place through disproportionation of (bipyrimidine)Pd(OAc) 2 to form a bipyrimidine-bridged dimer, which reacts with olefin to form a PdII-olefin adduct, followed by allylic C-H activation to produce (η3-allyl)PdII species. The (η3-allyl)PdII intermediate undergoes a reversible acetate attack to generate a Pd0-(allyl acetate) adduct, which subsequently reacts with p-benzoquinone to release allyl acetate and regenerate (bipyrimidine)Pd(OAc)2. No KIE is observed for the competition experiment between allylbenzene-d0 and allylbenzene-d5 (CD2=CDCD2C6H5), suggesting that allylic C-H activation is not rate-determining. Catalytic allylic acetoxylations of other terminal olefins as well as cyclohexene were also effected by (bipyrimidine)Pd(OAc)2.
Serial ligand catalysis: A highly selective allylic C-H oxidation
Chen, Mark S.,Prabagaran, Narayanasamy,Labenz, Nathan A.,White, M. Christina
, p. 6970 - 6971 (2007/10/03)
We are reporting a mild, chemo-, and highly regioselective Pd(II)-catalyzed allylic oxidation of α-olefins to furnish branched allylic esters that proceeds via a novel serial ligand catalysis mechanism in which two different ligands (i.e., vinyl sulfoxide 2 and BQ) interact sequentially with the metal to promote distinct steps of the catalytic cycle (i.e., C-H cleavage and π-allyl functionalization, respectively). Copyright