Enantioselective Intramolecular Cyclopropanations of Allylic and Homoallylic Diazoacetates and Diazoacetamides Using Chiral Dirhodium(II) Carboxamide Catalysts
作者:Michael P. Doyle、Richard E. Austin、A. Scott Bailey、Michael P. Dwyer、Alexey B. Dyatkin、Alexey V. Kalinin、Michelle M. Y. Kwan、Spiros Liras、Christopher J. Oalmann
DOI:10.1021/ja00126a016
日期:1995.5
counterparts, but allylicdiazoacetates are subject to greater variations in enantioselectivities with changes in substitution patterns on the carbon-carbon double bond. For example, the enantioselectivities in the intramolecularcyclopropanations of 3-allcyl/aryl-2(Z)-alken-l-y1 diazoacetates are generally 194%, whereas the cyclizations of the homologous 4-alkyl/aryl-3(Z)-alken1-yl diazoacetates are typically
Enantioselective, rhodium catalyzed intramolecular cyclopropanations of homoallylic diazoacetates.
作者:Stephen F. Martin、Christopher J. Oalmann、Spiros Liras
DOI:10.1016/s0040-4039(00)61761-6
日期:1992.11
The homoallylic diazoacetates 3a–j underwent enantioselectiveintramolecularcyclopropanation with the rhodiumcatalyst Rh2(5S-MEPY)4 (1) to give the oxabicyclo[4.1.0]heptanes 4a–j in 71–90% enantiomeric excess and in 55–80% chemical yield.
An Enzymatic Platform for the Highly Enantioselective and Stereodivergent Construction of Cyclopropyl‐δ‐lactones
作者:Xinkun Ren、Ningyu Liu、Ajay L. Chandgude、Rudi Fasan
DOI:10.1002/anie.202007953
日期:2020.11.23
carbene transfer mechanism for the asymmetric synthesis of cyclopropane‐fused‐δ‐lactones, which are key structural motifs found in many biologically active natural products. While hemin, wild‐type myoglobin, and other hemoproteins are unable to catalyze this reaction, the myoglobin scaffold could be remodeled by protein engineering to permit the intramolecular cyclopropanation of a broad spectrum of homoallylic