Asymmetric Conjugate Additions of Chiral Phosphonamide Anions to α,β-Unsaturated Carbonyl Compounds. A Versatile Method for Vicinally Substituted Chirons
作者:Stephen Hanessian、Arthur Gomtsyan、Nadia Malek
DOI:10.1021/jo000388g
日期:2000.9.1
Reactions of anions derived from chiral nonracemic allyl, crotyl, and cinnamyl bicyclic C(2)-symmetrical phosphonamides with alpha, beta-unsaturated cyclic ketones, esters, lactones, and lactams take place at the gamma-position of the reagents. The products are diastereomerically pure or enriched beta-substituted carbonylcompounds. The method also provides easy access to vicinal substitution of as
Cyclopropanation versus carbon–hydrogen insertion. The influences of substrate and catalyst on selectivity
作者:Michael P Doyle、Iain M Phillips
DOI:10.1016/s0040-4039(01)00408-7
日期:2001.4
Reactions of diazoacetates with varying linkages from the diazo-carbon to a vinyl group, catalyzed by chiral copper(I) and rhodium(II) compounds, were examined for selectivity in their intramolecularreactions. Bis-oxazoline-ligated copper(I) has advantages for cyclopropanation that form medium-to-large rings. Dirhodium(II) carboxamidates have advantages for small-ring-fused cyclopropane compounds
Total synthesis of (+)-pilosinine via a stereodivergent conjugate addition strategy
作者:Cassandra L. Schrank、Michael W. Danneman、Emily A. Prebihalo、Robert E. Anderson、Tyler J. Gibson、William M. Wuest、Richard J. Mullins
DOI:10.1016/j.tetlet.2020.151945
日期:2020.6
In recent work, asymmetricconjugateaddition reactions to chiral 4-phenyl-N-enoyl-1,3-oxazolidinones have been shown to give different stereochemical outcomes depending on the conditions employed. Through the application of stereodivergent reaction conditions, the totalsynthesis of (+)-pilosinine and the formal synthesis of (−)-pilosinine has been completed from a single enantiomer of the 1,3-oxazolidinone