General Enantioselective C−H Activation with Efficiently Tunable Cyclopentadienyl Ligands
作者:Zhi-Jun Jia、Christian Merten、Rajesh Gontla、Constantin G. Daniliuc、Andrey P. Antonchick、Herbert Waldmann
DOI:10.1002/anie.201611981
日期:2017.2.20
applicable chiral Cp ligand collection (JasCp ligands) with highly variable and adjustable structures. Their modular nature and their amenability to rapid structure variation enabled the efficientdiscovery of ligands for three enantioselective RhIII‐catalyzed C−H activation reactions, including one unprecedented transformation. This novel approach should enable the discovery of efficientchiral Cp ligands
Biocatalytic Asymmetric Dihydroxylation of Conjugated Mono- and Poly-alkenes to Yield Enantiopure Cycliccis-Diols
作者:Derek R. Boyd、Narain D. Sharma、Nigel I. Bowers、Ian N. Brannigan、Melanie R. Groocock、John F. Malone、Gareth McConville、Christopher C. R. Allen
DOI:10.1002/adsc.200505033
日期:2005.6
at benzylic or allylic centres. Competition from allylic hydroxylation of methyl groups was observed only when naphthalene dioxygenase was used as biocatalyst. The structures, enantiomeric excess values and absoluteconfigurations of the bioproducts, were determined by a combination of stereochemical correlation, spectroscopy (NMR and CD) and X-ray diffraction methods. cis-1,2-Diol metabolites from
Kinetic Resolution of Chiral α-Olefins Using Optically Active <i>ansa-</i>Zirconocene Polymerization Catalysts
作者:Cliff R. Baar、Christopher J. Levy、Endy Y.-J. Min、Lawrence M. Henling、Michael W. Day、John E. Bercaw
DOI:10.1021/ja040021j
日期:2004.7.1
and/or 4-positions. Due to the optically pure nature of these single site catalysts, they effect kineticresolution of racemic monomers: the polymeric product is enriched with the faster reacting enantiomer, while recovered monomer is enriched with the slower reacting enantiomer. The two components are easily separated. For most olefins surveyed, a partialkineticresolution was achieved (s = k(faster)/k(slower)
Reaction of dicyclopentadienylyttrium chloride with aldehydes and ketones. A novel cleavage reaction of CpY π-bond
作者:Changtao Qian、Aineng Qiu
DOI:10.1016/s0040-4039(00)88478-6
日期:1988.1
Dicyclopentadienylytrrium chloride reacts with aldehydes and ketones at 80°C in DME, generating fulvenes in excellent yields, while at lower temperature affording, after hydrolysis, cyclopentadienyl substituted alcohols.
Unusual fragmentation of fulvene endoperoxides with phenyliodosyl bis(trifluoroacetate) (PIFA)
作者:Galip Özer、Nurullah Saraçoǧlu、Metin Balci
DOI:10.1002/jhet.5570400319
日期:2003.5
Reaction of unsaturated fulveneendoperoxides with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate gave saturated fulveneendoperoxides containing the 1,2-dihydropyridazine ring. Treatment of dihydropyridazine endoperoxides with water followed by phenyliodosylbis(trifluoroacetate) oxidation provided acrylic acid derivatives and dimethyl pyridazine-3,6-dicarboxylate.