@article {143,
	title = {Scope of stereoselective Mn-mediated radical addition to chiral hydrazones and application in a formal synthesis of quinine.},
	journal = {Journal of Organic Chemistry},
	volume = {77},
	year = {2012},
	note = {CAPLUS AN 2012:213999(Journal; Online Computer File)},
	month = {2012///},
	pages = {3159 - 3180},
	publisher = {American Chemical Society},
	abstract = {Stereocontrolled Mn-mediated addn. of alkyl iodides to chiral N-acylhydrazones enables strategic C-C bond constructions at the stereogenic centers of chiral amines.  Applying this strategy to quinine suggested complementary synthetic approaches to construct C-C bonds attached at the nitrogen-bearing stereogenic center using multifunctional alkyl iodides, e.g, I, as radical precursors, or using multifunctional chiral N-acylhydrazones, e.g., II, as radical acceptors.  These were included among Mn-mediated radical addns. of various alkyl iodides to a range of chiral N-acylhydrazone radical acceptors, leading to the discovery that pyridine and alkene functionalities are incompatible.  In a revised strategy, these functionalities are avoided during the Mn-mediated radical addn. of I to chiral N-acylhydrazone II, which generated a key C-C bond with complete stereochem. control at the chiral amine carbon of quinine.  Subsequent elaboration included two sequential cyclizations to complete the azabicyclo[2.2.2]octane ring system.  Group selectivity between two 2-iodoethyl groups during the second cyclization favored an undesired azabicyclo[3.2.1]octane ring system, an outcome that was found to be consistent with transition state calcns. 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, completing a formal synthesis of quinine. [on SciFinder(R)]},
	keywords = {alkyl iodide acylhydrazone radical additive cyclization manganese, azabicyclooctane ring system stereoselective prepn, manganese radical addn cyclization mediator, quincorine prepn intermediate quinine, quinine formal synthesis},
	isbn = {0022-3263},
	author = {Friestad, Gregory K. and Ji, An and Baltrusaitis, Jonas and Korapala, Chandra Sekhar and Qin, Jun.}
}
