Asymmetric Amination\nof Unstrained C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Bonds

The asymmetric functionalization of unstrained C(sp<sup>3</sup>)–C(sp<sup>3</sup>) bonds could be a powerful strategy\nto\nstereoselectively reconstruct the backbone of an organic compound,\nbut such reactions are rare. Although allylic substitutions have been\nused frequently to construct C–C bonds by the cleavage of more\nreactive C–X bonds (X is usually an O atom of an ester) by\ntransition metals, the reverse process that involves the replacement\nof a C–C bond with a C–heteroatom bond is rare and generally\nconsidered thermodynamically unfavorable. We show that an unstrained,\ninert allylic C–C σ bond can be converted to a C–N\nbond stereoselectively via a designed solubility-control strategy,\nwhich makes the thermodynamically unfavorable process possible. The\nC–C bond amination occurs with a range of amine nucleophiles\nand cleaves multiple classes of alkyl C–C bonds in good yields\nwith high enantioselectivity. A novel resolution strategy is also\nreported that transforms racemic allylic amines to the corresponding\noptically active allylic amine by the sequential conversion of a C–N\nbond to a C–C bond and back to a C–N bond. Mechanistic\nstudies show that formation of the C–N bond is the rate-limiting\nstep and is driven by the low solubility of the salt formed from the\ncleaved alkyl group in a nonpolar solvent.