Scope and Mechanism of the Pt-Catalyzed Enantioselective Diboration of Monosubstituted Alkenes
作者:John R. Coombs、Fredrik Haeffner、Laura T. Kliman、James P. Morken
DOI:10.1021/ja4041016
日期:2013.7.31
The Pt-catalyzed enantioselective diboration of terminal alkenes can be accomplished in an enantioselective fashion in the presence of chiral phosphonite ligands. Optimal procedures and the substrate scope of this transformation are fully investigated. Reaction progress kinetic analysis and kinetic isotope effects suggest that the stereodefining step in the catalytic cycle is olefin migratory insertion
Asymmetric 1,4-Dihydroxylation of 1,3-Dienes by Catalytic Enantioselective Diboration
作者:Heather E. Burks、Laura T. Kliman、James P. Morken
DOI:10.1021/ja809610h
日期:2009.7.8
studies reported in this communication suggest that both cyclic and acyclic substrates will participate in this reaction; however, dienes which are unable to adopt the S-cis conformation are unreactive. For most substrates, 1,4-addition is the predominant pathway. In addition to oxidation to the derived 2-buten-1,4-diol, stereoselective carbonyl allylation with the intermediate bis(boronate) ester is
Carbohydrate-Catalyzed Enantioselective Alkene Diboration: Enhanced Reactivity of 1,2-Bonded Diboron Complexes
作者:Lichao Fang、Lu Yan、Fredrik Haeffner、James P. Morken
DOI:10.1021/jacs.5b13174
日期:2016.3.2
Catalytic enantioselective diboration of alkenes is accomplished with readily available carbohydrate-derived catalysts. Mechanistic experiments suggest the intermediacy of 1,2-bonded diboronates.
Analytical enantiomer separation of aliphatic diols as boronates and acetals by complexation gas chromatography
作者:V. Schurig、D. Wistuba
DOI:10.1016/s0040-4039(01)91399-1
日期:1984.1
Cyclic boronates and acetals of mono- and dialkylsubstituted 1,2-, 2,3- 1,3- & 1,4- diols have been quantitatively separated into enantiomers by complexationgaschromatography utilizing optically active metal chelates. An efficient, precise & sensitive method for determining enantiomeric purities for volatile glycols is thus available.
Cu(OTf)<sub>2</sub>-Catalyzed Selective Opening of Aryl and Vinyl Epoxides with Carbonyl Compounds to Give 1,3-Dioxolanes
作者:Pavel Krasik、Mathieu Bohemier-Bernard、Qing Yu
DOI:10.1055/s-2005-864795
日期:——
Copper(II) triflate catalyzes the ring-opening of aryl- and vinyl-substituted epoxides with various carbonyl compounds to furnish 1,3-dioxolanes under mild conditions. Alkyl- and alkoxycarbonyl-substituted epoxides remainunchanged under reaction conditions. This allows selective opening of aryl-substituted epoxides in the presence of alkyl-substituted ones.