A recyclable ‘boomerang’ polymer-supported ruthenium catalyst for olefin metathesis
作者:Mahmood Ahmed、Anthony G.M. Barrett、D.Christopher Braddock、Susan M. Cramp、Panayiotis A. Procopiou
DOI:10.1016/s0040-4039(99)01833-x
日期:1999.12
Polymer supported ruthenium catalyst 8 was found to be an effective catalyst for ring closing metathesis. The rate of reaction and activity was found to be comparable to that of homogeneous catalyst 1. In addition, the catalyst could be recycled and re-used up to three times by simple filtration. The residual ruthenium/catalyst content in the product mixtures using catalyst 8 were found to be much reduced
Cyclization/Hydrosilylation of Functionalized Dienes Catalyzed by a Cationic Palladium Phenanthroline Complex
作者:Ross A. Widenhoefer、Carmine N. Stengone
DOI:10.1021/jo9913006
日期:1999.11.1
Mixtures of(phen)PdMe2 (2a) and HBAr'(4) (3a) or (phen)PdMe(Cl) (2b) and NaBAr'(4) (3b) [phen = 1, 10-phenanthroline; Ar' = 3,5-C6H3(CF3)(2)] catalyzed the cyclization/hydrosilylation of functionalized 1,6-dienes to form silylated cyclopentanes in good yield and with excellent trans selectivity about the newly formed C-C bond (typically >50:1). A range of tertiary hydrosilanes were employed in the procedure although unhindered trialkylsilanes provided the most consistent results. The protocol tolerated a range of polar functionality including esters, ethers, amides, sulfones, and cyano groups. 4,4-Disubstitution on the diene backbone promoted cyclization, and a homoallylic ester, ketone, or ether directing group was required for efficient cyclization. The procedure tolerated dienes which possessed a single trans-substituted olefin and also tolerated allylic substitution. These substituted dienes underwent cyclization/hydrosilylation to form carbocycles resulting from transfer of the silyl group to the less hindered olefin. Mixtures of 2a and 3a also catalyzed the cyclization/hydrosilylation of functionalized 1,7-dienes to form silylated cyclohexane derivatives. Cyclization/hydrosilylation of 1,7-dienes was typically slower, less stereoselective, and more sensitive to substitution than was cyclization of 1,6-dienes.
GAMBARO, A.;PERUZZO, V.;MARTON, D., J. ORGANOMET. CHEM., 1983, 258, N 3, 291-296
作者:GAMBARO, A.、PERUZZO, V.、MARTON, D.
DOI:——
日期:——
Diallylmethylcarbinyl Acetate
作者:William G. Young、Lawrence J. Andrews、Stanley J. Cristol