title: Cyclic nitriles: diastereoselective alkylations.
abstract: [reaction: see text] Diastereoselective alkylations of metalated conformationally locked 4-tert-butylcyclohexanecarbonitrile are highly diastereoselective with magnesium and copper counterions but only modestly diastereoselective with lithium as the counterion. Selective generation of diverse metalated nitriles is readily achieved through bromine-magnesium, -copper, and -lithium exchange reactions of the corresponding bromonitrile or, for lithium, by deprotonating the parent nitrile with lithium diethylamide. Collectively, high alkylation stereoselectivities correlate with the retentive alkylations of C-metalated nitriles, whereas N-lithiated nitriles alkylate with modest selectivity, reflecting minimal steric differences in the corresponding axial and equatorial electrophile trajectories.
authors.affiliation: Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282-1530, USA. flemingf@duq.edu
authors.forename: Fraser F
authors.initials: FF
authors.lastname: Fleming
authors.forename: Subrahmanyam
authors.initials: S
authors.lastname: Gudipati
authors.forename: Zhiyu
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wang
authors.initials: W
authors.lastname: Liu
authors.forename: Omar W
authors.initials: OW
authors.lastname: Steward