Catalytic Enantioselective Hydroboration of Cyclopropenes
作者:Marina Rubina、Michael Rubin、Vladimir Gevorgyan
DOI:10.1021/ja034210y
日期:2003.6.1
2,2-Disubstituted cyclopropyl boronates have been synthesized with high degrees of diastereo- and enantioselectivity via the rhodium-catalyzed asymmetric hydroboration of 3,3-disubstituted cyclopropenes. A strong directing effect of ester and alkoxymethyl substituents has been demonstrated. The directing effect was found to be necessary in achieving high degrees of enantiomeric induction. Selected
Palladium-Catalyzed Hydrophosphorylation and Hydrophosphinylation of Cyclopropenes
作者:Bassam K. Alnasleh、William M. Sherrill、Michael Rubin
DOI:10.1021/ol8011138
日期:2008.8.7
Novel transition-metal-catalyzed addition of P-H entities across the cyclopropene double bond has been developed. This transformation allows for mild and efficient preparation of phosphorus-containing cyclopropanes in good yields and high degrees of diastereoselectivity.
Transition Metal-Catalyzed Hydro-, Sila-, and Stannastannation of Cyclopropenes: Stereo- and Regioselective Approach toward Multisubstituted Cyclopropyl Synthons
作者:Marina Rubina、Michael Rubin、Vladimir Gevorgyan
DOI:10.1021/ja027095k
日期:2002.10.1
The first highly efficient, stereo- and regioselective palladium-catalyzed hydro-, sila-, and stannastannation of cyclopropenes to give multisubstituted cyclopropylstannanes have been developed. It was shown that the addition across the double bond of cyclopropene is generally controlled by steric factors and proceeds from the least hindered face. The directing effect of alkoxymethyl substituents in the hydrostannation reaction of 3,3-disubstituted cyclopropenes was demonstrated. This methodology represents a powerful and atom-economic approach toward a wide variety of highly substituted cyclopropylstannanes, important building blocks unavailable by other methods.
Novel Organogermanium Compounds via Metalation of 3-Trimethylsilyl-3-ethoxycarbonylcyclopropene Derivatives
Preparation and full spectroscopic characterization of novel trimethylgermyl derivatives of 3-trimethylsilyl-3-ethoxycarbonylcyclopropenes (4-7) and 1,1-bis(trimethylgermyl)-3-trimethylsilyl-3-ethoxycarbonylallene (8) are described.