Diastereoselective Vinyl Addition to Chiral Hydrazones via Tandem Thiyl Radical Addition and Silicon-Tethered Cyclization
作者:Gregory K. Friestad、Sara E. Massari
DOI:10.1021/ol0067991
日期:2000.12.1
A diastereoselective method for addition of a vinyl group to alpha-hydroxy hydrazones under neutral tin-freeradicalcyclizationconditions, leading to substituted vinylglycinols, is presented. Tandem thiyl radical addition/cyclization upon a silicon-tethered vinyl group followed by treatment with potassium fluoride accomplishes a one-pot neutral vinyl addition process to afford acyclic allylic anti-hydrazino
A Silicon Tether Approach for Addition of Functionalized Radicals to Chiral α-Hydroxyhydrazones: Diastereoselective Additions of Hydroxymethyl and Vinyl Synthons
作者:Gregory K. Friestad、Sara E. Massari
DOI:10.1021/jo035405r
日期:2004.2.1
Stereocontrolled additions of hydroxymethyl and vinyl groups to chiral α-hydroxyhydrazones can be achieved by radical cyclizations using bromomethyl or vinyl radical precursors tethered via a temporarysiliconconnection. Tin-mediated 5-exo radical cyclization of α-hydroxyhydrazones using a silicon-tethered bromomethyl group, followed by oxidative removal of the tether, provides anti-2-hydrazino 1