Intermolecular radical addition to N-acylhydrazones as a stereocontrol strategy for alkaloid synthesis: formal synthesis of quinine
作者:Gregory K. Friestad、An Ji、Chandra Sekhar Korapala、Jun Qin
DOI:10.1039/c1ob05219e
日期:——
context of a totalsynthesis of quinine, generating new findings of functional group compatibility leading to a revised strategy. Completion of a formal synthesis of quinine is presented, validating the application of Mn-mediated radical addition as a useful new C–C bond construction method for alkaloid synthesis. The Mn-mediated addition generates the chiral amine substructure of quinine with complete
Aromatic N-heterocycles in Mn-mediated radical additions to N-acylhydrazones
作者:Manshu Li、Levi Goff、Gregory K. Friestad
DOI:10.1016/j.tetlet.2020.152058
日期:2020.7
Manganese-mediated radicaladdition reactions to chiral N-acylhydrazones produces amines with excellent stereocontrol, but prior work showed an incompatibility with aromatic N-heterocycles. Control reactions with various aromatic heterocycles as additives led to modified reaction conditions that permit improved radicaladditions to N-acylhydrazones in the presence of heteroaromatic compounds. The method
Scope of Stereoselective Mn-Mediated Radical Addition to Chiral Hydrazones and Application in a Formal Synthesis of Quinine
作者:Gregory K. Friestad、An Ji、Jonas Baltrusaitis、Chandra Sekhar Korapala、Jun Qin
DOI:10.1021/jo2026349
日期:2012.4.6
favored an undesired azabicyclo[3.2.1]octane ring system, an outcome that was found to be consistent with transition state calculations at the B3LYP/6-31G(d) level. Group differentiation at an earlier stage enabled an alternative regioconvergent pathway; this furnished the desired azabicyclo[2.2.2]octane ring system and afforded quincorine (21b), completing a formal synthesis of quinine.